fridge service parts

savagethegoat

Anyone got a source for parts for a Electrolux RM122F?

Doesn't seem to work too well on 12v, fine on gas but I'd like to replace as much as is practical DIY.

Tried to find someone to overhaul it in Cork City without success.

Any advice appreciated

Jaysus no need overhaul it it's just a switched resistor, fairly primitive electrical setup...not even a thermostat.
Even when they are wired correctly and all tickety boo they don't work well on 12volt.

What are the symptoms?
Which part isn't working?
What size is the element?
What gauge and length are the wires for the battery?

crabbypaddy

As liam says they don't work well on 12v.

RM122 element is rated 75w, the gas is rated 140g/24 hours which works out at about 160w hence the difference in performance.

There are much higher wattage elements for other models you could possibly fit but 75w will flatten your leisure battery quick enough anyway, you don't want to be drawing 135w. Gas is the best option for stationary. Or chuck it an get a compressor fridge.

If you have weedy wires to the fridge you could be dropping a few watts too.

crabbypaddy

As liam says they don't work well on 12v.

RM122 element is rated 75w, the gas is rated 140g/24 hours which works out at about 160w hence the difference in performance.

There are much higher wattage elements for other models you could possibly fit but 75w will flatten your leisure battery quick enough anyway, you don't want to be drawing 135w. Gas is the best option for stationary. Or chuck it an get a compressor fridge.

If you have weedy wires to the fridge you could be dropping a few watts too.

It'd be far more effective stick a few 500ml bottles of frozen water in the fridge before setting off than most electrical solutions. Stoopid absorption fridges (no offence..mine included) no bloody thermostat on the gas either.

So if you shouldn't use a domestic compressor fridge after moving until the gas settles, what's so special about the Danfoss ones you can? Or do they just gloss over that suggestion?

savagethegoat

Sir Liamalot wrote: »

Jaysus no need overhaul it it's just a switched resistor, fairly primitive electrical setup...not even a thermostat.
Even when they are wired correctly and all tickety boo they don't work well on 12volt.

What are the symptoms?
Which part isn't working?
What size is the element?
What gauge and length are the wires for the battery?

no offense but if I knew that would I be asking?




I can't change the fridge as it would mean structural changes to the van, which I don't want to do and were I to put a few bottles of frozen water in the fridge, I'd get nothing else in. The Fridge is very small.

It won't flatten the battery as I intend using on 12v only when driving, I can use the gas when parked.

all I need to know is what service parts can I get for the 12v system that I can fit myself and where can I get them.

spaceHopper

Skip the water get a letter of milk and freeze it or freeze the sausages... Have one too and it 12V won't cool the fridge after 3 hours of driving it's not up to anything at all.

crabbypaddy

savagethegoat wrote: »

all I need to know is what service parts can I get for the 12v system that I can fit myself and where can I get them.

What everyone is trying to point out that in all likelyhood theres nothing wrong with your fridge, they just don't work well on 12v. Its quite simply a 12v heating element shoved up against a tube in the fridge.

If you want to test it disconnect the 12v wiring for the fridge at the panel / relay and measure the resistance it should be about 2 ohms. If its much higher, then test the resistance of the element, the switch in the fridge.

http://www.pathoranmotors.com/ would be able to get an element or switch if you need one.

savagethegoat

thanks for the link. That's useful

I don't have any facility to measure the resistance and I'd suggest that 99%+ of people wouldn't. That's why I'm asking for help and advice.

I suspected it would be the heating element, is it a DIY job to fit a new one? (especially if you don't have a multimeter and wouldn't know how to use it if you did)

(btw it was working better originally I believe )

crabbypaddy

savagethegoat wrote: »

thanks for the link. That's useful

I don't have any facility to measure the resistance and I'd suggest that 99%+ of people wouldn't. That's why I'm asking for help and advice.

I suspected it would be the heating element, is it a DIY job to fit a new one? (especially if you don't have a multimeter and wouldn't know how to use it if you did)

(btw it was working better originally I believe )

edit : Found a new one for a similar fridge at £48 +p&p on ebay. I think I'll try taking out the element and seeing if it heats up first!

I'd say Tristan in pat horan would have it fitted and all for that money if you're in that neck of the woods.

One thought you haven't left on the winter cover on the vent?

Other cause of loss of efficiency I can think of:

• Winter cover not removed, vent blocked / air circulation impeded.
• Metal cover securing insulation around element is open / insulation loose thus losing heat.
• Gas has stratified / crystals have formed blocking the internal tubes
• (turn upsidedown for a few hours / overnight, then upright for a few hours before relighting can improve the operation)

Ways to improve efficiency:
Add a fan to the condenser to improve air circulation. I have an 80mm pc fan cable tied to our condenser.

savagethegoat

it works OK on gas, There is no winter cover, it lives undercover in the winter. Fridge hasn't been used since the autumn set in

savagethegoat

savagethegoat wrote: »

... if I knew that would I be asking?

If you are taking the thing apart anyway then maybe have a look and find out because they're relevant questions to the operation of the appliance?

Basic diagnostics are a lot cheaper than throwing money at a thing. €2 gets you a multimeter but I really don't recommend using one that cheap on anything above 50V.
Most people have access to one but lots of them don't think they're necessary.

Actually my fridge works so well on 12v it freezes the fridge contents. :rolleyes:
But I usually have a packed fridge already at temperature. With correct condenser baffling and active cooling. Also a 125W element on 10mm² cable.
I just use AC while driving mostly.

You could overhaul the lot:
Switch: €10
Two relays: €10
Element: €50
Bag of lucars: €5
New conductors (minimum 2.5mm²): €10
but I don't see the point, some basic diagnostics and you could just address the part that's not working.

You might be able to stick a larger element into it if it fits and won't melt anything.

It could just be a spider nest needs cleaning out of back.

Ventilation plays a big part too.
Even if the gas is working now it'll work better for less gas after the ventilation is addressed correctly.

savagethegoat

I've been investigating and I believe the relay was wired wrongly. Would you have a look at this for me?

it was 30 battery,85 ignition,86 earth 87 fridge

it should be I think 30 fridge,85 ignition, 86 earth, 87 battery,

(in fact the ignition wire comes from the alternator direct and thus the fridge 12v only works with the engine running, fine by me) )

Now I have 12v+ on the battery feed to the relay, but this drops to maybe 5v once it's attached to the relay...is that a normal voltage drop? presumably it's because the fridge is drawing some of the power.? I thought it may be the relay and so fitted a new one with no change.

The relay was wired correctly if you're into alternator switching. 85 and 86 are the coil terminals.

The voltage drop is because the power cables are too long and thin.

savagethegoat

savagethegoat wrote: »

I think i'm still wrong

30 fridge 87 battery,85 ignition,86 earth

is that it?

30 battery, 87 fridge
You don't need that relay though it's only advisory to prevent battery drain. Should be a 7.5A or 10A fuse /DC MCB at the battery end also.

savagethegoat

you'll have to explain a bit more than that...sorry. Do I actually need a relay if the alternator is switching on and off? Could the thick wire from the battery not come straight from the alternator and go direct to the fridge?


How would there be a voltage drop due to long thin wires if there is full voltage at the wire going into the relay? The drop seems to be in the relay. DOens';t make sense to me.

savagethegoat

there is a fuse fitted, haven't checked it's rating.

So if I trace back the thick battery wire and fit that to the alternator in lieu of the 85 86 wiring and relay, will that help? It seems the drop is at the relay, if the thick wire led direct to the fridge it would be shorter and 12v

I actually think I'm getting somewhere....no wonder the frisge doesn't work at 5v! (I presume

What gauge and length are the power wires?
Too thin cable will act as a resistor and dissipate power, throttling the fridge. Sounds like it's running at about half power.

The relay is only to prevent you from powering it with the engine off. It's a failsafe. Usually wired from the D+ or dash battery light. Means you can't run if from PV and things...not that you may want to.
No need to be messing with the alternator you can just wire it direct from the battery and use the fridge switch.
If it's a 10A relay the contactor surface area will be poor too and might be playing a part.
Find some 2.5mm^2 flex cable (30amp) and try running it on that to see if it improves.
Beware the battery voltage will sag if you try powering it without running a charger though.

Could also be a poor terminations. If you can pull the crimps to the relay from the wires by hand they're bad and a fire hazard.

Oh right. Well if the cables are thick enough then yeah just shorten the run and bypass the relay or use a larger one.

Maybe the relay is scuppered, could be carbonised contacts. You can check it for resistance while the coil is powered or open it and eyeball it.

savagethegoat

Sir Liamalot wrote: »

What gauge and length are the power wires?
Too thin cable will act as a resistor and dissipate power, throttling the fridge. Sounds like it's running at about half power.

The relay is only to prevent you from powering it with the engine off. It's a failsafe. Usually wired from the D+ or dash battery light. Means you can't run if from PV and things...not that you may want to.
No need to be messing with the alternator you can just wire it direct from the battery and use the fridge switch.
If it's a 10A relay the contactor surface area will be poor too and might be playing a part.
Find some 2.5mm^2 flex cable (30amp) and try running it on that to see if it improves.
Beware the battery voltage will sag if you try powering it without running a charger though.

I'd prefer to keep the alternator switching tbh as it's fail safe.
It 's a good thick yellow wire and it registers 12v+ at the relay, but if you connect it to the relay and then m,easure off the terminal you've connected to, the voltage is about 5v, I don't undertand why that would be.
COnnections all seem good and it's now a brand new relay.

savagethegoat

I think the best thing would be to abandon the existing wiring and run new cable direct from alternator to fridge, re=routing to a much shorter length, I'll get some cable in the week. where would be best place I wonder to find it? Maplin?

I'd need to fit a suitable on off switch too as the existing switch is right up in the roof.


Thanks for help

I was on the phone but the blighterin' screen is too small. Ok you've got thick cables going from the alternator to the battery..that's great she'll charge nicely. Thick to me is as wide as a little finger so sometimes easier to deal in mm². The wire going from the alternator to the 85 terminal of the relay does not need to be any more than standard 10 amp flex 1.5mm². Same for the ground on the 86 terminal.
From the battery to the 30 terminal needs to be at least 2.5mm² and same for the 87 terminal to the fridge and the fridge negative to battery negative or chassis.


Jaysus don't ever buy cable from Maplin, robbin' rip-off-merchants charge more for the half meter than most people do by the meter. If you're in Dublin Demense in Tallaght have up to 200mm², but most electrical wholesalers will have what you need...don't ask the guy in the shop what you need because they'll just give you 10A cable, smallest you want is 30A stranded flex, preferably black and red. A good motor factors will stock it too for slightly more and usually in single cores.

5v is very low I'm surprised the light on the switch illuminates at that. Are you sure you're not running the fridge power through the relay coil? The fridge definately isn't working at that and that's more than just a cable gauge issue. What's the voltage when you bypass the relay and link the 30 an 87 terminal manually (it'll probably spark a little if you do it with the fridge powered (no need to turn engine on) you'll be grand though)?

Just for test purposes you can crimp together all three cores of an extension lead x2 (pos + neg) and see if it solves you problems. This way you can determine if it's the relay,wiring or both.

Best move the relay to beside the battery so the coil wires are longest (doesn't matter) and the power wires are shortest (matters a lot).
Some people fuse the coil positive...it's good practice too. Others rely on the thin cable acting as fuse wire. I just piggy back the 30 terminal that's already fused and hot as long as I can use the same rated cable for both.

savagethegoat

savagethegoat wrote: »

you'll have to explain a bit more than that...sorry. Do I actually need a relay if the alternator is switching on and off? Could the thick wire from the battery not come straight from the alternator and go direct to the fridge?

The alternator is wired to the battery. If you do that the fridge switch would be permanently powered.

savagethegoat

savagethegoat wrote: »

Now I have 12v+ on the battery feed to the relay, but this drops to maybe 5v once it's attached to the relay...is that a normal voltage drop?

Nope any more than 1 volt is excessive. In an ideal setup it wouldn't drop at all but that's very expensive to wire. iirc mine drops 0.5V.

savagethegoat wrote: »

It 's a good thick yellow wire and it registers 12v+ at the relay, but if you connect it to the relay and then m,easure off the terminal you've connected to, the voltage is about 5v, I don't undertand why that would be.

If you measure it no load you'll get a much higher reading than under load. It's not a sign the relay is at fault just a circuit voltage instead of an end of a live wire voltage.

savagethegoat

Sir Liamalot wrote: »

The alternator is wired to the battery. If you do that the fridge switch would be permanently powered.

there is currently a cable going direct from the alternator to the relay. This is only live when the engine is running obviously. what I propose is running new cable from where this is connected direct to the fridge (via a fuse and a switch so I can isolate it if the fridge isn't required.. The fridge would then only be running when the engine was running.

The rest I don't understand I'm afraid

The more I think about it the more likely it sounds to be a corroded ground termination. That or your cables are a mile long.

Here's some schemetics on the subject fresh off the presses.

The cable dimensions denote conductor cross-sectional area or CSA which is the standard grading of cable and signifies the amount of electrons you can fit down them.

You can make it as simple of complicated as you need or want it.

savagethegoat

savagethegoat wrote: »

there is currently a cable going direct from the alternator to the relay. This is only live when the engine is running obviously. what I propose is running new cable from where this is connected direct to the fridge

There's at least two wires at the back of your alternator neither are suitable for what you are suggesting. The thin one is off when the engine is off and will be destroyed if you try to power a fridge from it (but you can power a relay coil with it). The thick one is always on.

savagethegoat

OK so I will have to scrub that bit then.

I will look at eliminating the relay though if that isn't necessary, and moving the switch from the back of the van where I can't see it to the dash where I would see a warning light when it's on. Fridge could be wired direct from battery then.

I can't understand how there can be a good 12v in the wire but this drops if the wire is attached to the relay measured on the input terminal.

I think as a first step I shall bypass the relay and see if the fridge then works.(obviously with the engine running)

savagethegoat

savagethegoat wrote: »

OK so I will have to scrub that bit then.

Always the best place to start.

savagethegoat wrote: »

I will look at eliminating the relay though if that isn't necessary,

Works for me because I never use it..and I have a large enough battery to forgive me after a single night's abuse even if I did.

savagethegoat wrote: »

...and moving the switch from the back of the van where I can't see it to the dash where I would see a warning light when it's on. Fridge could be wired direct from battery then.

Ah no the whole point of using relays is so you can keep your power runs as short as possible. Running the positive to the dash and back to the fridge is never going to work. You can wire a manual illuminated switch in the dash that controls the relay but keep the power leads as short as possible.

savagethegoat wrote: »

I can't understand how there can be a good 12v in the wire but this drops if the wire is attached to the relay measured on the input terminal.

It's like you said earlier the circuit under power uses some.
The 12volt you are seeing is the battery open circuit. The 5V is the circuit voltage, to include the voltage drop on the wiring and appliance and crusty terminations et al.


Also possible reasons: it works fine and your battery is brown bread.
You're using a different ground point under test and bypassing the alleged problematic one.

savagethegoat wrote: »

I think as a first step I shall bypass the relay and see if the fridge then works.(obviously with the engine running)

If you bypass the relay you don't need to run the engine, because you've bypassed the engine failsafe. Although you will still want to charge the battery so it doesn't get hammered.

Those Dometic switches give trouble too, although usually only if you use them as switches...they can soot up internally and reduce conductivity.

savagethegoat

running from the battery to the dash to the fridge will be a shorter run than the current route, almost the shortest possible.

Battery condition doesn't come into it as it is only on when the engine is running and in any case would be coming from the leisure battery which isn't going to stop the vn starting the next morning if it runs down a bit

surely if there is 12v going into the relay, there should be 12v coming out the other side when it's open and going on to the fridge.

I don't want to run the fridge on 12v at any other time than when I am driving.

How long is the cable run in meters so? I may have underestimated the cable you need.

Battery condition comes into it if it's cream crackered and your alternator is running full field trying to charge dead cells. Check the battery terminal voltage under load with a voltmeter if it's 5V get rid before it leaks.

True, well should be ~14V in ~14v out. Is there 12volt going in though or do you disconnect the cable in order to test it?

savagethegoat

the wire when disconnected is approx. 12 v+ when connected and measured on the terminal it's connnected to it has dropped off the scale. I can't understand that. surely there should still be 12v+ at that stage before the relay is opened?

Could be a crap termination, rusted up, insulation not stripped properly, loose from overheating or not compressed properly, lots of things. Sometimes it's quicker just reterminate as you go.

If when you measure 5v at the relay, check the battery and if the battery is 12v the problem is downstream. If the battery is 5V case closed it's feckered.

An open switch = not operating, a closed switch = operating.
If the relay is open it should be 12v at the 30 terminal and 0v at the 87.
If the relay is closed it will read the same voltage at the 30 terminal and the 87 which is not necessarily going to be 12v in a problematic circuit. Just pull the holder back enough so you can get a test probe on the relay blade but don't disconnect it next time.

It should be 12v in and out but that's the issue we're trying to resolve. It doesn't mean the relay is the problem that's just the test point.

savagethegoat

terminal is bright and shiny and tight, relay is new (replaced old one unnecessarily in all likelihood). I'm sure that's not it.

As i keep saying, the feed from the battery is 12v+ (pprobably 13.5 according to the reading on the dash gauge)

Measured on the input terminal with wire attached, it's probably 5v . It doesn't make sense.Anything that wire is properly attached to should read the same as the wire, surely.

and the connecting females are perfect too?

V=IR
Heavy loads cause voltage drop.
https://en.wikipedia.org/wiki/Voltage_drop

savagethegoat

anyway, drawing a line under all that.....I need a 12v feed to the fridge which for some reason I don't have. This may be the reason the fridge isn't working too good on 12 v. I have 12 volts before the relay so I am going to temporarily bypass the relay and see what the fridge does when it has 12v connected. This will tell me if the element works or not, which is what I really need to know.

savagethegoat

I'll report back tomorrow.. :-)

Thanks fro brainstorming session.

It's gtting a bit clearer to me

savagethegoat

OK checked terminals on relay they are all correct now. with fridge switched off there is full voltage arriving at the relay. With fridge on this drops as I guess would be normal. Both batteries are charging Ok it seems.

Thinking laterally, the only thing actually running off the leisure batteries is the inside lights with the addition of the fridge running via it when driving. I actually don't need the leisure battery at all really as I tend not to use the lights anyway (go to sleep when it's dark, wake after dawn...) but I think I'll leave it running the fridge so that the main battery is separate from the fridge.

Van is sitting outside running with fridge on to see if it's working. There is power going to the fridge and the circuit for the former sparker is isolated.

If the fridge doesn't cool down in a reasonable time, I'll get a new element as I think that's about the only bit that could be faulty.

savagethegoat

OK checked terminals on relay they are all correct now. with fridge switched off there is full voltage arriving at the relay. With fridge on this drops as I guess would be normal. Both batteries are charging Ok it seems.

Thinking laterally, the only thing actually running off the leisure batteries is the inside lights with the addition of the fridge running via it when driving. I actually don't need the leisure battery at all really as I tend not to use the lights anyway (go to sleep when it's dark, wake after dawn...) but I think I'll leave it running the fridge so that the main battery is separate from the fridge.

Van is sitting outside running with fridge on to see if it's working. There is power going to the fridge and the circuit for the former sparker is isolated.

If the fridge doesn't cool down in a reasonable time, I'll get a new element as I think that's about the only bit that could be faulty.

A drop of 9v is not normal. Did you check the battery voltage under load? Did you have an accurate portable voltmeter? How long are the cables and what gauge?
Have you a thermometer in the fridge now or an ice tray?
I can tell from here your element isn't the problem.

savagethegoat

as I have said before I have neither a multimeter or know how to use one . I have a basic voltmeter that checks battery and alternator condition so it is no doubt very inaccurate to use it the way I am. The fridge does seem to be getting colder though.... and the battery is holding it's own.

savagethegoat

just checked it...it is definitely working now, possibly not brilliantly but enough to maintain the cold after running on gas when parked. Thanks for the help.

An auto-ranging multimeter works pretty much the same way an alternator tester does except with more accuracy and features for the same money.
Pretty essential tool for electrical work.

Alls well that ends well.

savagethegoat

another problem now. Why won't my fridge stay alight? Sometimes it goes out for no particular reason or goes out when you slam the door. Sometimes it stays alight for hours
Does it need a new jet I wonder or can I clean the existing jet?
Would it be the regulator at fault?
any idea what jet I would need for a Electrolux RM122F. It's the old model , not compatible with the newer ones hence I can't just buy a replacement.

(Gets lovely and hot on 12v so I assume that's OK now)

edit:
I've dismantled what I could and cleaned and it's running away nicely on gas at present.

savagethegoat

savagethegoat wrote: »

(Gets lovely and hot on 12v so I assume that's OK now)

Some fans would save you a lottov gas and boost the cooling performance. The idea is to remove heat.


It's possible your pilot light is misaligned to the vent and it keeps getting blown out with the door pressure/driving.

savagethegoat

Sir Liamalot wrote: »

Some fans would save you a lottov gas and boost the cooling performance. The idea is to remove heat.


It's possible your pilot light is misaligned to the vent and it keeps getting blown out with the door pressure/driving.

I meant the element and the flue are getting nice and hot....the idea being to exchange heat in the heat exchanger I imagine. Anyway, it stayed alight much better post clean up, with ice forming and when switched to 12v, maintained that ice for an hour before I shut it down, so I think I've got it cracked as far as you can with an old fridge.

Thanks for the reply

The pilot/element heats the evaporator which pulls heat from the fridge innards transfers it to a condenser that tries to vent it to the atmosphere it's a thermodynamic cycle. If you cool the condenser it can do the same work for less buthane/electrons which also means it'll do more work (get colder in warmer ambient) for the same power.

Fair play on the guerilla service. If you baffle the pilot light you'll stand a much better chance that gusts won't extinguish it.