TR2/3/3A Question about front turning blinker wires

[2billydavies]

Hi guys... me again. Wiring question for you all.
Just getting the front grill on my TR3a and hooking the front turning blinkers up with the wiring.
I have 3 wires on each side going into each of the two front turning blinkers (inside the grill).
Problem is, there are only 2 screws to plug the wires into on each lamp. The colored wires go into these screws, which I clearly marked when taking it all apart before my engine rebuild.
However, on each side, there is a single black wire that appears to go "nowhere." For the life of me I can't remember where it went when I took it apart.... clearly didn't label it because I would easily "remember" it when I put it back together, which I cannot of course.
Any idea what these two wires are and where they go? My first guess is a ground wires for each front turning blinker lamp, but they have no connectors on the ends of them and I can't find anywhere where they would have screwed down onto the frame of the car or anything. They are only so long, so just holding them and looking around with the length of the wire in hand, I can't find anywhere to put them.

I do have the ground wires for the actual headlights hooked up. I simply bolted them to one of the bolts that holds the horn down to the frame (on each side, one ground on each horn). All of the lights work fine.... even the front blinkers where this mysterious black wire is just hanging out of the wiring harness.

Thoughts? Ideas? Should I just cap it off and tuck them away?

Thanks! ~ Billy

 

[Geo Hahn]

You are correct that the black wires are ground.

I do not recall having ground wires to my front lamps but since they are available I would definitely use them -- you can never have too many grounds.

I do not quite understand 'there are only 2 screws to plug the wires into on each lamp' as I do not recall screws (would have expected wires from the fixture to bullet connectors), but if that is what you have then that's okay -- the ground wires can be attached using one of the mounting screws for the lamp fixture.

 

[2billydavies]

Thanks Geo. I'm going to ground them. And yes, on each front blinker lamps (the ones on the widemouth grill) the wires are connected to them with two screws. Sort of like the starter button on the dash board. put each wire in the little hole, tighten the screws to hold them in.

My descriptive writing probably isn't the greatest. And I use a lot of "that thing" to describe different parts of the car. I'm horrible with the actual names of the parts. lol.
thanks a ton.

 

[Andrew Mace]

I have 3 wires on each side going into each of the two front turning blinkers (inside the grill).
Problem is, there are only 2 screws to plug the wires into on each lamp. ...

Your description leads me to wonder what lamps you have on the front; they don't sound like the original Lucas L594 lamp with the glass "beehive" lens to me? Any photos?

 

[TR3driver]

Just a thought : Are you taking the boots off to look for the connections? I've seen several cars where DPO's apparently couldn't figure out how they came apart, and added connections at the back of the lamp. The other possibility is that you have non-original lamp holders in the front. I believe all originals used bullet connectors inside the boot. There should be a simple loop of sheet metal for the ground bullet connector. This isn't the right bulbholder, but the ground connection should be very similar on the front turn/marker lamps for a TR3A.


PS, I see Andy got in while I was looking for a good illustration. Oh well

 

[2billydavies]

Hmmmm... I'm not sure if these are the originals or not. Here are two pics. You cannot see the black ground wire I was talking about as it is up above the inside grill, both sticking out of the wire harness. They work fine, even without those two black ground wires connected to anything. I'm going to go ahead and ground both of them though based on your suggestions. Thanks.

 

[Geo Hahn]

Interesting - and I'd say definitely not original.

I'd be tempted to stick some shrink tube over those connections since they are otherwise exposed.

 

[TR3driver]

Doesn't look original to me. The boot may be a cut-down original, but the socket (and the mounting) are not.

The bulb has to be grounded somehow in order to work properly. Dual filament bulbs can be confusing sometimes, as the second filament can serve as a ground under some circumstances, giving you a lamp that goes out when both filaments are supposed to be lit. Or, you may be getting enough ground at the moment through the mounting to the grill and the grill mounting to the body. But aluminum corrodes very easily and aluminum oxide is a poor conductor (which is why aluminum wiring is no longer allowed in houses). You'll definitely have less trouble in the future if you run a separate ground wire. There should be a spring clip bolted to the body, behind each horn, that takes a ground wire bullet from the turn signal and another from the headlight.

At the rear, Triumph relied on the mountings to provide grounds for the lamps. I recommend adding a ground wire there for better reliability (and brighter lights). I daisy-chained a single black wire with bullets for each fixture, then brought it around to one of the fuel tank mounting bolts (which also has a ground wire for the fuel tank sender).

 

[2billydavies]

oh wow.... good stuff. Ok, so let me ask you... where do I hook the ground wire from the bulb? I know where the clips are behind the horn so I'm good on that end... do I screw the ground into one of the screws in the pic above? My electricity knowledge isn't where my mechanical ability is. lol. thanks!

 

[TR3driver]

Since there doesn't seem to be a ground connection easily available, I might just go to one of the mounting screws. The other option (which I would probably do) would be to pull the socket out of the grille & boot, to see what's going on in there.

Actually, the third option is to source the correct socket. The entire assembly, including glass beehive lens & chrome trim ring is only about $25 (or less if you shop around); or you can get just the bulbholder and boot for about half that (from TRF).

 

[2billydavies]

Thanks a ton Randall. I didn't realize these were not original.
One final question on this... the two black ground wires that are not connected to anything right now... do you still suggest grounding them as well even though I plan on grounding the lights? I'm guessing yes, but i'm hardly the pro at electricity. thanks so much for the help... this forum rocks!

 

[TR3driver]

I'm missing something. I thought you were going to use the two black wires to ground the lights. Are you saying that you're going to run new wires instead?

Hmm, maybe a few words of explanation might help : For anything to work off a car battery, it must have a complete circuit to both terminals of the battery. Commonly, the car body/chassis is used as one of the conductors to complete the circuit. Making a connection to the body is called "grounding" (or "earthing") even though it has nothing to do with actual dirt. But there is nothing magical about it, it's just a funny shaped wire (from an electrical standpoint).

 

[Marvin Gruber]

Late to the party, there should three wires there or the bulb holder is self grding. One is (red wire) parking light, the other will be green and for the blinker. Can you post a picture of the inside of the bulb holder.
marv