Rear Demister Not Working-Help Please?

mazerooni

Hi All! I have a 00 1.25 Fiesta and the rear demisters are not working. My brother is apprentice mechanic and he checked all the fuses and they are working fine. Any ideas on what the problem could be? Is it costly to replace the heated strips if I do have to replace them? Thanks!

crosstownk

It could be the switch. Check to see if you're getting a live to the rear window.

EPM

Are the connectors at either end of the window attached? If its covered on your insurance...cough cough...

mazerooni

crosstownk wrote: »

It could be the switch. Check to see if you're getting a live to the rear window.

Sorry to sound stupid but how do I do this? The light comes on alright when I press the boutton on but it just doesn't demist the rear screen.

mazerooni

EPM wrote: »

Are the connectors at either end of the window attached? If its covered on your insurance...cough cough...

yup the connectors are attached. I must look up my policy to see just in case I do have to replace them!

Esel

I don't think you are getting EPM's not so subtle hint.... the implication is that you might have glass coverage on your policy, so if your rear window 'somehow' got broken or cracked, it would be replaced without charge.

There may be a break in one of the heater lines - this can even happen from careless cleaning - you should really only wipe the inside of the glass in the direction of the lines. You can buy a bottle of liquid conductor in a motor factors which will set rapidly, and will repair the break, if there is one.

zilog_jones

There are contact plates to the right of the boot sill, they look like this:



There are also corresponding pins on the edge of the hatch door. Make sure none of these are broken and the contacts are clean (use some fine sandpaper and WD40). I have to clean these frequently on mine otherwise the rear wiper stops working. The boot light is also controlled by these.

mazerooni

esel wrote: »

I don't think you are getting EPM's not so subtle hint.... the implication is that you might have glass coverage on your policy, so if your rear window 'somehow' got broken or cracked, it would be replaced without charge.

There may be a break in one of the heater lines - this can even happen from careless cleaning - you should really only wipe the inside of the glass in the direction of the lines. You can buy a bottle of liquid conductor in a motor factors which will set rapidly, and will repair the break, if there is one.

Oh right haha, didn't get that not so subtle message at all! I might try get one of those bottles of liquid conductors before I resort to that!

mazerooni

zilog_jones wrote: »

There are contact plates to the right of the boot sill, they look like this:



There are also corresponding pins on the edge of the hatch door. Make sure none of these are broken and the contacts are clean (use some fine sandpaper and WD40). I have to clean these frequently on mine otherwise the rear wiper stops working. The boot light is also controlled by these.

Ok, I have never checked those things before, sdidn't even notice them really! Sometimes my rear wiper doesn't work and then sometimes it does so might clean those later. Thanks!

zilog_jones

If you have an intermittent rear wiper too I'd be almost certain it's those contacts that are the source of your problems.

antodeco

Not trying to hijack the thread but I have a similar problem. Except its 3 of the bars arent working. Could this just be old age or something that liquid conductors could fit?

peasant

antodeco wrote: »

Not trying to hijack the thread but I have a similar problem. Except its 3 of the bars arent working. Could this just be old age or something that liquid conductors could fit?

The "bars" are actually printed on when the screen is made.
The ink contains silver paint (for conductivity) and tiny glass particles that melt into the screen as it is heated to be shaped and toughened.

But those bars do stand proud of the surface and load or window scrapers (or something else) rubbing off them can break of little bits. As soon as that happens the circuit is broken and the bars don't heat up anymore.
There is repair paste available to patch the broken bit, but that doesn't always work and comes off quite easily again.

If all else fails a new screen has to be put in.

antodeco

I might try that paste. Its the bars right in the middle, so cant see properly. Ill have a little look later on. Dont fancy getting a rear window, cause I dont think they are readily available

mazerooni

zilog_jones wrote: »

There are contact plates to the right of the boot sill, they look like this:



There are also corresponding pins on the edge of the hatch door. Make sure none of these are broken and the contacts are clean (use some fine sandpaper and WD40). I have to clean these frequently on mine otherwise the rear wiper stops working. The boot light is also controlled by these.

Thanks for your help! Just wondering do those contacts have anything to do with the alarm rthat goes off when u leave the headlights on and turn engine off when you open the door. Sometimes this alarm works and other times it doesn't so I have ended up eaving my lights on by accident! Thankfully battery didn't go flat!

mazerooni

By the way will that make my car fail NCT? Or would they only check it if the rear screen was fogged up?

zilog_jones

Rear wiper and window heaters are not tested in the NCT. Re: headlight buzzer, there is are switches in the driver and passenger door frames (near the hinges) that control the buzzer and the ceiling light thing. These can get sticky.

mazerooni

zilog_jones wrote: »

Rear wiper and window heaters are not tested in the NCT. Re: headlight buzzer, there is are switches in the driver and passenger door frames (near the hinges) that control the buzzer and the ceiling light thing. These can get sticky.

Thanks for your wisdom! I checked those pins and plate yokes and one plate is pretty badly damaged so reckon that's the source of my problems. Must set bout getting those replaced ASAP!