Curse you Lord Lucas

[PATR8]

Driving home tonight and my low beam goes out, no problem I have a spare light at home. Swap the light out and .... it is not the light. I would guess it is something to do with the reason my lights don't flip. I have given up on light flips this summer

 

[RomanH]

Check the front ground points.

 

[DrEntropy]

Just the low beam? Poor connection in the solid blue wire at the bucket or the three prong connector at the bulb... since ya changed the bulb and had the same condition the connection at the bucket pigtail or the center three-way are suspect. It ~could~ be the ground, but usually if so you'd see at least a glow from the low beam filament.

 

[tr8todd]

I'm a big fan of that CRC electrical contact cleaner. Whenever I pull apart any electrical connection on the 8, I always give the connection a little squirt. The secret to fixing the electrical gremlins is a test light and a good wire diagram. Follow the electricity till it isn't there any more. There's your problem. Or work backwards from where it isn't. It also nice to have a garage full of spares to swap out suspect parts.

 

[DrEntropy]

It also nice to have a garage full of spares to swap out suspect parts.

The bane of my existence! Hovel, garage and Shed... Alfa, Lotus, MG and Benz bits. To the rafters. At least many of the English car pieces are in common from Loti to MG.
Alfa and Benz not so much. :crazy:

 

[swift6]

Had that happen on both of mine. First one side, then the other. First time the headlight would come and go, then it was dim. Second one just went out. I knew wha tit was right off the second time after some lengthy exploring on the first one.

I checked grounds, I cleaned connectors, I swapped lenses. All to no effect.
It seemed that the wires flex everytime the headlights go up and down. As the grommets harden and the wire insulation hardens over time, the ability for the wires to flex lessens. The wires eventually crack and create a short. On the second light, one wire broke clean in half.

At some point I will do all new wires from the bucket out to the loom in the engine bay, but for now, I spliced in new wire at the flex points. Made it a little longer and made sure it would stay out of the way as the headlights cycled up and down. They have been fine ever since.

 

[GregW]

Driving home tonight and my <span style="font-weight: bold">low beam goes</span> out, no problem I have a spare light at home. Swap the light out and .... it is not the light. I would guess it is something to do with the reason my lights <span style="font-weight: bold">don't flip</span>. I have given up on light flips this summer

I'd start with checking the high beam switch

 

[DrEntropy]

I took it to be just one lamp out on low beam, Greg. That would rule out the switch, methinks.

 

[DNK]

Major, did you follow that conversation about the relays for the headlights on the mailing list?

 

[GregW]

Yeah, there may be a couple problem spots. If the high beams haven't worked for a while, but the lows did, that makes me lean away from a bad ground and towards the switch. It is a common point between the two circuits and can take a beating.

 

[DNK]

Shoe Size?

 

[GregW]

I changed that.

 

[DrEntropy]

Changed yer shoe size?!? wow. :smirk:

On a TR7 the lights are relay'd, but I thought both lows were on the same one, highs another (?).

 

[PATR8]

OK, a little clarification, It is just the low beam on the passanger side. The lights stopped flipping last fall, two probably unrelated problems unless it is in the loom maybe. I will check the blue wire and clean up the connectors tonight and break out the test light

 

[DrEntropy]

Then the electrons from the "common" leg of the solid blue feed to that light pod are no longer "emboldened" to fight their way to the filament. You'll find the 'blockage'. :thumbsup:

 

[Gliderman8]

https://www.britishcarforum.com/bcforum/u...oday#Post674123

 

[Andrew Mace]

...The lights stopped flipping last fall, two probably unrelated problems unless it is in the loom maybe. ...

I will be curious to know how you ultimately solve the no-flip problem. Why, the rest of you ask? Because I am joining the "dark side" (kidding; I like ALL Triumphs!) of the Triumph universe with a very early '79 TR7 convertible, which has somewhat similar problems (among others, but that's for another post). One of the headlights seems to go up and down ok, but the other one is much more tempermental. It probably doesn't help that some DPO managed to wire just the up-and-down circuit of the headlights through a universal horn button mounted under the dash! I really can't wait to see more of this mis-wiring up close, but first I have to free off the clutch and get the car from the seller's house to mine and start some serious work after the car's 10-year nap!

 

[DrEntropy]

"Oh, th' stories we could tell...


...If it all blows up an' goes to heck..."

 

[MDCanaday]

The problem is very likely to be in the fuse block.Over time the fuses get nasty and you have just enough voltage drop to keep the relay from doing its job.BTDT.
Di-electric grease on the end of each fuse can take care of this after contacts are cleaned.As long as your at it do all the grounds with the same TLC,and I will bet a cold one your light woes are over.
MD(mad dog)

 

[swift6]

Changed yer shoe size?!? wow. :smirk:

On a TR7 the lights are relay'd, but I thought both lows were on the same one, highs another (?).

Only the light motors are relayed. The lights themselves are not. All the juice goes through the switch. Relaying the headlights is a common upgrade.