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Trailer Indicator relay

Posted: Wed Jan 17, 2007 12:30 am
by MQ SWB
My car has a 4 pin relay for the left and one for the right indicater before going to the trailer plug, problem is I'm not getting any power to the plug and the relays click when turned on ( hence no indicators for the trailer) when I take out the relay and bridge 2 wires it gets power any help appreciated
Dixie

Posted: Wed Jan 17, 2007 6:04 am
by -Scott-
At a guess: the car's indicator circuit is switching the relay coil, but there's no power coming IN to the contacts.

When you jump the two wires, I guess you're connecting the coil feed to the contacts out - and everything works. So you need to find a continuous power feed coming TO the relay contacts - do any of the relay wires have a constant 12V (24V?)

Does this help?

Scott

Posted: Wed Jan 17, 2007 2:10 pm
by Dooley
Well this is how I think it should be wired up.

Those boxes are the relay coils, a left or right indicator circuit energises the coils and closes the switch. You have 12V going through the switch part then that goes to the indicator lamps, they're LEDs here because LEDs were quicker to find and I couldn't find a lamp symbol anyway.

Ignore the random numbers. Also I'm not an auto electrician so not sure if it uses the relay to flash the lamps or whether there should be some other circuitry, however that to me is how the relay should be wired.

Image


Some automotive relays have a picture on them that look like those schematic symbols. The side with the switch picture should have 12V through it hooked up to the lamps and the coil bit should be hooked up to the indicator circuit.

I'll do up a quick paint pic of how to physically do it.

Image

Posted: Mon Feb 12, 2007 12:40 pm
by mcfqn
mate, i had the same problem with my prado wiring. I checked the fuses inside the cabin first, all ok, so ripped off the rear panels, found the relays and bridged them just like you did. i identified what each wire did in the circuit and found that i had no power to the relays. thinking there was a short or a cut wire i traced the little sucker through the cabin, through the firewall and into the main fuse box under the bonnet. I pulled every damm fuse out, thinking i was wasting my time, until i got to the last 10A fuse which had blown!! well didn't i feel stupid. the drawing on the fuse box lid did not show the trailer loom fuse so i didn't think to check in the first place.

i don't know if you have already checked your fuses (all of them!) but that would be my suggestion.

have you also tried swapping relays i.e. left one in the right socket and vice versa? also you could try giving the relays power from another source like a cig lighter wire just to confirm it is a power supply issue.

hope that helps.