vhf affecting bilge pump

irish snowblower

I have an automatic bilge pump with a manual over ride switch on dash. My problem is when I press the botton on the vhf mic to talk it turns on the bilge pump on and affects the transmission of the vhf. Anyone any ideas on a possible fix? Thanks in advance

fergal.b

Thats a good one they must be jumped off the same live instead of having there own fuse.





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irish snowblower

I will have a look at that

ado100

irish snowblower wrote: »

I have an automatic bilge pump with a manual over ride switch on dash. My problem is when I press the botton on the vhf mic to talk it turns on the bilge pump on and affects the transmission of the vhf. Anyone any ideas on a possible fix? Thanks in advance

You could try using fewer expletives in your VHF broadcasts - the bilge pump will eventually get bored and switch itself off!:D

Glenalla

irish snowblower wrote: »

I have an automatic bilge pump with a manual over ride switch on dash. My problem is when I press the botton on the vhf mic to talk it turns on the bilge pump on and affects the transmission of the vhf. Anyone any ideas on a possible fix? Thanks in advance

This should not happen. A VHF should be wired directly to the battery through its own fuse so in the event of a general electrical failure power will still be maintained to the VHF to allow for transmissions to be made in the event of an emergency where the electrical system has failed.
I suggest you call a marine electrician to re-wire your VHF and also to survey your entire electrical system as this should never have happened in the first place and would place a question mark over what else has happened that is not considered good practice and may put your electrical system at risk. Poorly installed electrical systems can cause fires on-board.

irish snowblower

The boat in question is a 4m rib with only vhf, nav lights and bilge pump drawing power from a common feed to the dash from the battery. I will run a seperate feed from the battery to the vhf and see what happens then. Thanks for replies.

fergal.b

Do you know if one the switches for the bilge pump is working off the earth wire.







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irish snowblower

I dont know it will be saturday morning before I can get at it in good light

Glenalla

irish snowblower wrote: »

I dont know it will be saturday morning before I can get at it in good light

Hi Snowblower, if it is only a small RIB with minimal electrics it would an easy task to wire the VHF directly and also give you peace of mind that no other items will be on the circuit. It is quite a simple task you can do yourself.

irish snowblower

Tried wiring the vhf directly(temporary) to the battery and it still turned on the bilge pump when the button was pressed. I am going to connect the vhf to a second seperate battery tomorrow and see what happens then. If all else fails I can always hit one of them with a big hammer the only question is which one?

fergal.b

Did you disconnect everything else and just wire the VHF, it has to be working as a switch unless the bilge pump is radio controlled





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irish snowblower

No I did not disconnect anything else. It will have to wait till tomorrow it is too cold in the shed now

irish snowblower

Latest update. I wired the vhf to a seperate battery and left bilge pump as normal on boats battery pressed the button and bilge pump came on. I reconnected the vhf to boats battery and connected the auto wires of the bilge pump to seperate battery but left the manual live wire to boats battery pressed the button and pump came on, disconnect the manual live and it does not come on. Two other points to note are if I disconnect the aerial from the vhf and press the button nothing happens also when the vhf is affecting the bilge pump the transmission is badly affected. The bilge pump is automatic but there is a float switch in the bottom of it (not electronic). I know I have to replace something but which one, is the vhf affecting the bilge or the other way around.

fergal.b

So with the VHF wired to it's own battery it still set off the bilge pump was the VHF still connected to a common earth maybe the housing that holds it, if you can disconnect the earth going to the bilge pump and press the button on the vhf if nothing happens then try it with the live, that should give you an idea of what wire is making the circuit. Are you sure the float switch hasn't got a built in electronic switch it would be strange not to.





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irish snowblower

The vhf is in a fiberglass consol so no earthing there and no common earth. When I say there is no electronics in the pump there is a switch but nothing more that could be affected by a signal(or is there?)

fergal.b

Is this the set up have also is the float switch and pump setting in water "just wondering could there be a leak in the float switch and the water is making a connection"
Are you near Co.Dublin I would love to see this with my own eyes

irish snowblower

The float switch is built into the bilge pump. The automatic positive wire goes direct to the battery through a fuse, the manual positive goes to the switch on the dash so there is no off position on the switch ( the switch is auto, auto, manual) I am in Laois. The boat is in a shed on a trailer bone dry so no water causing problems P.M. sent

irish snowblower

Yes Fergal there is a sensor in the bilge pump rather than a switch which the vhf seems to be able to affect. I have changed the wiring on the switch in the dash to give an off/auto/manual control for the bilge pump which has fixed the problem. Thanks to all who have replied and specially Fergal B who found the problem.

Mech1

I know nothing about boats, but have you checked the groundplane of your antenna? Just wondering, and I recon the pump / radio manufacturers would / should be interested in helping you sort this without just bypassing the problem with a switch.

Daibheid

irish snowblower wrote: »

...... other points to note are if I disconnect the aerial from the vhf and press the button nothing happens also when the vhf is affecting the bilge pump the transmission is badly affected. ...... I know I have to replace something but which one, is the vhf affecting the bilge or the other way around.

Transmit without an aerial and you'll probably wind up replacing the VHF as well. That power has to go somewhere so you should never press transmit without an aerial.