Electrical Help

[Bking]

Hi, I have a MK4 mondeo hatchback 2008, I have fitted a tow bar and tried to wire it up using a 7 way bypass relay but have all sorts of problems.

Has any one had this problem and could offer some advice. :(

Brian

[al2052]

what are the problems

[Bking]

Hi Alan, When I put my brake lights on all the running lights come on as well. the fog lights do not come on at all with the switch but do come on with the lights. I have a tester that plugs into the N12 socket, that comes on running lights on its own hours later.

I have purchased another relay just in case the first one is faulty and I am going to have another go when it stops raining.

I have a Haines manual but the wiring diagram colours do not match the car.

Good A.

Thanks Brian

[al2052]

It sounds like a mismatch on the input side of the relay, I would double check the the wiring colours because I have found Haynes accurate on the few I have checked, also disconnect outputs from relay and check at relay with meter before reconnecting. also double check input wiring with voltmeter.

[al2052]

Further thoughts:

Disconnect all inputs and keep power supply to relay, then reconnect one by one and check output at socket each time you connect one, if fault still on first one then try another, then connect each input step by step, this should help to identify where the problem area is.

each input should operate each output individually without others connected with power to the relay.

hope this helps

[Bking]

Hi again Alan, I have stripped out and started again, thing is I can only get a pulse signal with a meter 0.01 of a volt.

I have rigged up a bulb so I am going to test with that. Its a very good idea to connect them one at a time thanks.

Brian

[al2052]

Yes it will be pulsed, usually so quick to not notice on lights so depends on equipment used to read, the bypass relay converts this pulsed voltage into a constant voltage so same results could be checked on output at socket for each connection without using meter or bulb.

[Bking]

Hi Alan, thanks for all your help. I did the wiring again and fitted the new relay , then tested with a indicator bulb and blow the left hand side lights, spent 2 hours looking for the fuse then came on the site and found the solution. ran out of time so will test tomorrow.

Brian