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Triumph TR6 - Observations about replacement bulb holders

My somewhat long running electrical gremlin problems have been partially and perhaps temporarily solved--I have brake lights and rear lights!

I did all the trouble shooting and couldn't get power from the left rear to the right rear on the tail lights, so I redid all the connections on the left side and the right side. Still didn't work. So I ran a jumper from left to right-that got me power. So, I rewired the tail lights with the proper colored wire and new connections, and it all works.

Here's the comments:
1. The replacement taillight/brake bulb holders do not ground the same way the originals do. There is a seperate spade terminal that has to be wired directly to ground. This isn't a major issue and is probably a better design.
2. Even after I had power and ground to the right side, I couldn't get the tailight to light, although the brake light worked. I tried a direct connection to the battery, still no luck. Finally, I took the rubber boot or whatever off the bulb holder and looked at it real good-there was some kind of film on the inside of the contact that prevented current flow. After cleaning that off with my Dremel tool, everything was fine.
3. I think the wiring harness between the left and right side is damaged where it is hidden behind the trunk. I still can't get power to the right rear side marker light and the back up lights don't work.
3. If I can find one, I'm going to just order a new rear harness. The Moss catalog has them for 72 and up, for about $80, but not for 71. Maybe I can make one, which I guess would involve pulling the old one out and copying it.
4. These problems are very frustrating, but it was also quite rewarding to get it fixed!

John
JL Bryan

Hi John
I would have a go at making a new rear harness as there aren't a lot of wires involved, $80 seems a lot for just a few wires! It is also quite easy to remove the old one from the car, the only problem might be reusing the old connector plug at the front, can't remember how the wires are attached to it
Ron
R. Algie

Ron, what you're saying is true. If it wasn't a hobby and stress reliever, it would be insane to spend the amount of time I have spent on an $80 problem which is still only partially fixed.

Actually, the only wiring I can't figure out from looking at everything is the rear marker lights. They each have 2 wires; neither on the right hand side has power, and I recall that the left hand side at least had power with the regular lights on. The other lead is probably, I am guessing, for the parking lights circuit. But right now, I'm not really up to pulling the rear harness out and making a new one, although I bet it couldn't take make than a few hours, assuming I could figure out the connector or reuse it. Maybe when our weather isn't so nice, I'll have a go at it if I don't first find a harness.

John
JL Bryan

TRF has it for $79. That sounds like a pretty good deal in light of all the troubles I have had. Gonna check it out!

John
JL Bryan

John
When re doing my rear lights during the restore, I replaced all the disconnect connections.
Keep in mind that all power to the right side is from the left side..meaning..there is a double disconnect (2 connections) or a join in the wiring harness to take the power to the right side equivalent (except R turn). Your R side marker is powered from the left. With all this in mind, I would suggest you have a problem with the wiring harness as it disappers behind the inner body skin. You do not mention if you have licence plate marker illumination working. This comes off the wiring harness right in the middle of the "hidden" harness.
Before you go out and spend the bargain price of $79, why not try replacing just that short section at the back of the car. The entire rear harness which connects at a grey MOLEX connector which is behind the driver side left "kick" panel sends power to the transmission tunnel courtesy light, gas level sending unit,trunk light, rear marker lights, brake,back up, plate illumination, and R and L turn. It sounds like your only problem is right side. The problem is "fishing" a new wiring harness. Here is what I suggest: Cut all wires on right side so u have just the wire. Tape them together and also tape to the wires a length of good strong string. As you pull the wiring harness out your string will travel behind/between the outer body and inner body skins. You now have a means of pulling a new wire harness through. As for the licence plate wires(2) cut them and attach a second string to them. It will go through the hidden area also and when pulling the 2 strings back the 2 wires for the plate illumination will come out where you want them to. A good electronics store will have double insulated disconnect connectors. One solid "spade" female which attaches to left running light, the second flat spade, male, is where the new female flat spade attaches and goes to R side. Your R side marker light can be from a double disconnect connector on the R side tail running light and I think this is currently how it is powered anyway. A picture of this connector is here..PN 6460.
http://www.icorally.com/products/solderless_terminals_tools/page39.html
You will only need to "fish" across 4 wires ( plus 2 for the plate illumination). Ground, Back up, R turn, and running lights. In theory the ground could be eliminated but you may as well send it across. Tape your new harness up and "break out" your plate 2 wires at a measured distance down your new harness.
Sorry long and drawn out but will work...I promise! This might cost u all of 10 bucks.
Hope this works for you John
Regards
Rick C
Rick Crawford

Rick, thanks. The plate illumination light works. The transmission tunnel light does not, but I haven't tried to trouble shoot it yet to see if it has power. The brakes and rear taillights now work. That leaves only the right rear marker light and both back up lights not working. The brakes and taillights were the most critical to me, so I fixed them first.

Radio Shack has the proper sized female connectors for the spade connectors on the bulb holders.

My hesitancy is that there are, for reasons I don't understand, 2 leads going into the right rear marker light. I recall that when I replaced the two connectors on the left marker, one of them had power, the other did not. The wiring diagram isn't real clear to me as to why there are 2 leads on the right--if they were set up like the brake light, the left side would have 2 wires, 1 for power to the left side and 1 to take the power to the right. But why would the right rear marker have 2 leads; it isn't a ground. I am guessing that that the markers are wired to both the main lights and the parking lights, so that would explain the 2 sets of leads.

I'll play with it some more. Getting the wires through the concealed area at the back of the trunk wasn't a problem. Also, I need to be sure I have the gauge right as the Brit wires are measured by "strands" and the american by "guage". This is all very interesting, you know. I may just label everything on the left and then pull it out and redo all of the left to right wiring.

John
JL Bryan

John
QUOTE "I am guessing that that the markers are wired to both the main lights and the parking lights, so that would explain the 2 sets of leads".
Nope. The 2 wires to the side marker are power and ground. They can only be that. They are wired yes to the headlight switch. Wired to the parking light position with is also a connection to the head light position. That is why the marker/tail lights stay on when you go to the headlight position.
The tranny tunnel light is most likely a bad ground or bulb holder connection. Keep in mind that, that light should come on when a door is opened. It also has 2 other positions on the slide switch for "always on" or "always off" (plus the door open)...total: 3 positions.
Some of your wires traveling in the hidden area at back of car are GAGA.....a very technical electronics word.
Acceptable automotive wiring gauge is 16 or even 18 for a marker light.
You are deffinitely on the right track and by next weekend you should have joy with all your lights.
Have fun
Rick C
Rick Crawford

Hi Guys!

I'm just finishing the install of my new wiring harness that I purchased locally, and I just today discovered the web site for the actual manufacturer. It would appear that they sell retail and can provide lots of bits including tools etc. Some prices are shown, some you must request a quote.

If anyone has gone through them direct, it would be interesting to hear from you.

http://www.britishwiring.com/
Mati Holland

This thread was discussed between 01/03/2004 and 03/03/2004

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