The Triumph Dolomite Club - Discussion Forum

Hello all

I’ve wired in a halogen headlights conversion following the below diagram.



Simple enough I thought. Except no. The lights work on the master switch - sidelights, then dipped as normal - but when I use the stalk for mainbeam all headlights work but then stay on! The master switch or column stalk won’t turn the lights off. They only turn off when I turn the ignition off! I’ve checked the relays again tonight and they are wired as per the diagram. I’m guessing the live feed could be the problem, but I’m guessing! I’ve tried a nos master switch, and different column stalk, but still have the same issue!!

Any ideas welcome.

The only thing that can be the cause is that the blue/white from the switch is still connected to the lamps. In other words, the switch is not just switching the relais but the lamps also. When main is put on, the relais goes on. At that point you can switch the switch to low beam again but a loop is created as the lamps activate the relais and around.

Twin headlamps have two blue/whites from the switch to the lamps. You have to cut both. All two have to be connected to the 87 and only one from the switch side is needed on the 85. The picture is not quite right as the 85 is ground and the 86 is feed, wrong in your pic. Some relais have diodes in them and when using those the 85 and 86 mixed up isn't that good and will create a fire somewhere..

For the main beam I alway's use a slightly more expensive 5 pin relais with a double 87 contact, not te be mixed up by a changeover 87 and 87a 5 pin. Using a double 87 pin relais will give an easier and neater installation using two seperate contacts for the outers and the inners.

In the pic below is the diagram of the fitting manual of my kits.

Jeroen

Bish wrote: ↑Tue Jun 16, 2020 11:04 pm The master switch or column stalk won’t turn the lights off. They only turn off when I turn the ignition off!

That would happen if you have treated the points on the diagram where wires of a like colour cross as joins. They should not be.

Yes, there has to be a short between pin 85 and 87 on, at least, the main beam relay.
When the lights are latched on, see if they go off when one or both connectors are pulled off from the 85 pins. If they do go off, and they don't go back on when the pins are re-connected, that shows it's a short causing the pronblem.

Graham

Thanks for the replies.

I can’t see a second blue / white wire in the loom by the inner wing.
Maybe I need to be looking further forward and mount the relays forward of the battery?

GrahamFountain wrote: ↑Wed Jun 17, 2020 7:28 pm Yes, there has to be a short between pin 85 and 87 on, at least, the main beam relay.

No there doesn't. That will latch the relay on which is exactly the incorrect behaviour Bish describes. The stalk does the latching. It's a Triumph not a Poxhall.

tinweevil wrote: ↑Wed Jun 17, 2020 8:18 pm

GrahamFountain wrote: ↑Wed Jun 17, 2020 7:28 pm Yes, there has to be a short between pin 85 and 87 on, at least, the main beam relay.

No there doesn't. That will latch the relay on which is exactly the incorrect behaviour Bish describes. The stalk does the latching. It's a Triumph not a Poxhall.

You didn't think I meant "there should be" a short rather than "there must be", i.e. to explain the described behaviour, did you?

That would have been a truly and stupendously dumb thing for any professional electronics (avionics) engineer to have meant!

Graham

Thanks again for the replies.

I think I’ve cracked it tonight. I think I had a dodgy relay on the mainbeam side of wiring. It seems to have been sticking on if that’s possible? It was getting rather hot too! It was a bit of a cheapo from eBay. I’ve swapped it over for another, better quality, relay. All the lights seem to be working fine now

I really should stop buying crap parts.

GrahamFountain wrote: ↑Wed Jun 17, 2020 10:04 pm You didn't think I meant "there should be" a short rather than "there must be", i.e. to explain the described behaviour, did you?

That would have been a truly and stupendously dumb thing for any professional electronics (avionics) engineer to have meant!
Graham

Apologies Graham, that is exactly what I thought you meant.

When I fitted relays to the 1850, I used the 4 pin relays with built-in fuses. eBay is a potential minefield although PayPal is heavily on the side of buyers provided you have already paid for your item.

I think it’s a couple of lessons learned for me.

1 - don’t take a diagram to be correct just because it’s there.
2 - don’t trust new parts just because they are new. They may be of dubious quality.

Not too worried about the duff relay and trying to get my money back. Maybe I had damaged it whilst wiring it in incorrectly?

I have wired the relays in as per Jeroen’s suggestion.

87 pin - headlights side.
86 pin - column side.
85 pin - earth.
30 - power from ignition side of fuse box.

Works fine at the moment. Hopefully I can now move on to the next job on the car.

Cheers, Bish.

Bish wrote: ↑Wed Jun 17, 2020 10:35 pm Thanks again for the replies.

I think I’ve cracked it tonight. I think I had a dodgy relay on the mainbeam side of wiring. It seems to have been sticking on if that’s possible? It was getting rather hot too! It was a bit of a cheapo from eBay. I’ve swapped it over for another, better quality, relay. All the lights seem to be working fine now

I really should stop buying crap parts.

It's certainly possible the short between the 85 and 87 pins was internal to the relay. And Tinweevil was right that such a short would basically be the only way to get such a relay to latch-up until power was removed.

As to the other bit, I know the subtleties in the use of auxiliary verbs is one of the nightmares of English grammar. I chaired a British Standards Institute committee (ACE/6/-/9) and was UK rep to AECMA's C2/GT9 for 20 years, and we frequently had to deal with that issue and give definitions for should, shall, must, etc. So perhaps I ought to have known to reinforce the relationship to what the cause has to be rather than what the solution should be.

Graham

Graham

Bish wrote: ↑Thu Jun 18, 2020 8:12 am I think it’s a couple of lessons learned for me.

1 - don’t take a diagram to be correct just because it’s there.

I can't see anything wrong with the diagram at least.

However, re-reading the fault description, that suggests that the fuses were connected to the power that's switched by the ignition, or the relay wouldn't have unlatched when that was turned off - you'd have had to disconnect the battery.

Are you sure you want the lights powered that way rather than off the unswitched side, as normal?

Graham

Bish wrote: ↑Thu Jun 18, 2020 8:12 am I have wired the relays in as per Jeroen’s suggestion.

87 pin - headlights side.
86 pin - column side.
85 pin - earth.
30 - power from ignition side of fuse box.

I have the 30 on the brown side directly put on the take off on the battery cable but battery will be fine also. 30 on the switched side isn't advised as all the light feeds go through the ignition switch and a few extra meters cable.

The drawing does work that way but currently a lot of universal 4 and 5 pin relays have a diode fitted over the coil. These cannot be fitted as in the drawing and create immediately a short to ground when switched on. That's why it's the best to use 85 as ground and 86 as pos feed so nothing can happen during installation or replacement.

Jeroen