scoobyster

I am fitting halogen headlights to an old Triumph with quad lamps, originally fitted with sealed units but they've blown and were crap anyway. I've got the halogen kit from Rimmer Bros (Triumph specialist) but the instructions were missing. I'd cope if I was using normal bosch-type relays but they've included a 5 pin lucas relay.

They have only included one relay so somehow it must be possible to use this to control both main and high beams - but I can't fathom how without 2 seperate triggers and supplies. Someone on the Triumph Dolomite forum told me it was possible to use a 5 pin relay but he couldn't remember how - that forum is down at the moment.

The Lucas relay has pins labeled C1, C2, W1, W2, and the fifth pin is unlabeled but looks like it's probably a second C1 (which would make very little sense!) I understand C1 = 30, C2 = 87, etc, but don't see how this single relay can control both main and high beam circuits. It is quite large so potentially could contain two switches but it's sealed so I can't check.

Can the Lucas be used or should I just bin it and get two Bosch relays? Probably need to make a trip to Maplin to get fuses and spades etc anyway.

Chelspeed

A big lucas relay about two inches long with a pressed steel cover crimped over? I've seen one of these years ago and it was only a single pole relay.

So I think you're right, get a pair of modern 4 pin relays.

alcazar

iTrader: (2)

That Lucas relay was the one ALL rally cars used to control their sets of Cibies, and Biode headlights.

I would assume that the kit you have uses the relay to trigger the DIP beam when the main beam is selected, so as to have both at once?

In all honesty, you really DON'T need to relay the lights on an older car, the stock wiring was well up to the job, so the above would make sense.

You can use the Lucas relay, (haven't seen one in YEARS, we used to go round scrappys and pay about 2 shillings for them (10p), as they were over a couple of quid each to buy new).

You are right in thinking that the terminals are as follows:

W1= 85
W2= 86

C1= 30
C2= 87

Use a circuit tester to check if the unmarked terminal is another 87, and if it is, it allows you to feed TWO lights from the one relay without recourse to piggyback connectors etc. You can get more modern relays with the same double 87 configuration.

Oh.............there's NOWT wrong wi' Lucas relays. They WERE the best, and are still better than cheapys from the far east and as good as any Bosch one. IIRC they were rated at 45A, as the same relay was also used to control early Lucas alternators, the ones that had remote-fitted control boxes to avoid heat, vibration etc, like on rally cars, which were rated at 45A. 11 AC they were called.

Alcazar

scoobyster

Thanks for the replies. Yes it's a pressed steel covered one - Lucas 6RA, rated at 20A.

The car is a '72 Triumph 1500 (same shell as used later for the Dolomite) and the original lamps where 2x twin-filament (dipped and full beams) and 2x single filament (full beam only) sealed units. The replacement lamps are 2x H4 and 2x H1, so achieve the same thing. Would there be any gain real gain in lighting both filaments at the same time in the H4 lamps? Is this usual? If so then maybe that is what the kit intends. In reality it's unnecessary as this is no rally car

I think I've read that the headlight switch is considered weak, so I was worried about upping from 35/40W to 55/60W per lamp. If my concern is unfounded then I can just forget about relaying and save a job. Should I just suck it and see? Maybe I should phone Rimmer Bros and see what they actually intended!

Thanks again for your help.

scoobyster

Triumph forum is back up and a guy on there thinks that the switch contacts can burn out with the current drawn by halogens. It seems to have happened to another member as his halogen high beams have stopped working but flash still works.

They suggest relaying only the H1 pair of high beam lamps and leaving the H4 pair powered through the switch. He reckons if you relay both pairs that the current drawn through the switch is too low and corrosion can collect on the contacts without being burned off by the current. Seems a bit far fetched to me but what do you think Alcazar? Just relaying the high-beam-only pair of lamps seems a good solution to me, and perhaps what the kit intended.

alcazar

iTrader: (2)

Yes, reading the post above, it seems that it is for relaying the H1 high beams. I have to admit that I hadn't taken into account the increase in wattage, and thus, current, going from the older sealed beam units, to newer halogens.

Basically, then, you need to connect the relay as follows:

FROM headlight main beam, (behind one of the H4 connectors), to relay terminal W1. I usually use a Scotchlok type connector here.

From relay terminal W2 to a suitable earth.

FROM battery +ve via suitable fuse to relay terminal C1

From relay terminal C2 (or C2s if both ARE C2) to the inner lights.

Finally, don't forget to earth both inner lights too.

HTH, Alcazar

NB: "Suitable earth"......battery earth is good
"Suitable fuse".......DON'T buy one of those cartridge type that used to be sold for audio equipment connection use. A decent blade type should be available. For two 55W halogens, you're needing 10A, but I'd put a 15A in to allow for surge.