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Wiring relay for halogen headlights

Posted: Tue Dec 26, 2006 3:50 pm
by Jamp
Hi All

I've got the halogen kit for my 1500 from Rimmer Bros but they didn't include the instructions and said they would forward them later but haven't done so. I can't be bothered to chase them as I want to get them installed this week, so am after some advice re the relay wiring. They've included a Lucas relay with 5 terminals, 4 of which are labeled C1 C2 W1 W2, the fifth looks like it may be a second C1 but is unlabeled.

I was expecting 6 terminals - effectively 30 for power (fused - not included in the kit :() and 86 for earth, then 85(i) and 87(i) for trigger and supply for main beam, and 85(ii) and 87(ii) for trigger and supply for high beams. I don't see how a 5 terminal relay can achieve this - it is a big heavy relay though and is all they've included.

Anyone have any advice or should I just bin the Lucas relay and use two normal Bosch-type relays, one for main and one for high beams. I'd prefer to use the Lucas as it'd save me a long trip to Maplin.

Cheers,

Ben

Posted: Tue Dec 26, 2006 8:24 pm
by 1300dolly
it can be done with the 5 teminal but i couldn't tell you how from memory. if you want to be lazy pop into hellfrauds and they do a pre wired relay kit complete with idiot guide.

Posted: Tue Dec 26, 2006 9:54 pm
by Lewis
They do? Fantastic?

My main beam contacts are shot, burnt out from the halogens. Flash still works mind....then again, I guess the contacts could be OK but something mechanical could be amiss. In fact, it might even have relays on it. Not even looked!

Yet to investigate :)

Posted: Tue Dec 26, 2006 10:50 pm
by Nick C
I've heard that the contacts on the column switch can fail if the whole system is relayed, as they corrode without the full current to burn the corrosion off. The solution I was given was to relay just the inner main beams, leaving the outer beams running through the switch, so there is enough current to keep the contacts clean, but not enough to burn them out.

Posted: Fri Dec 29, 2006 1:09 am
by Jamp
Thanks for the replies.

Nick, relaying the inner pair sounds a good solution. Is the switch the only weak point likely to suffer from the higher current drawn by the halogens? If so I will just do as you suggest and relay the inner pair. Would you suggest doing this under the dash, triggering from the switch, or just forget the inner pair's loom and trigger from the outter pair's high beams and power direct from the battery?

Ive seen...

Posted: Fri Dec 29, 2006 10:35 am
by Jon Tilson
loads of burnt out switches in my time so I would reckon a realy is essential for the halogen inners.
Ive not heard of Nicks theory beofre but I suppose its plausible. I do find as a general rule that its the low current electrcis that give grief, except the horn.

I'd fuse the inners, feed direct from the fuse box to the power side of the relay and on to the lights. Then take the realy control switch feed from the existing main beam circuit. If that doesnt make sense ask again...

Jonners