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Triumph TR6 - Tunnel Light

Does anyone (Doug) know where the ground lead grounds to on the Tunnel lamp? Does the wire just go back into the wire bundle and ground down the line??
I didn't even think there was a separate ground on that light. I figured the switch leg grounding to the body would do the same thing.
Don
DON KELLY

Don
The OE wire harness has the ground (Black)part of the wire harness. The NEW tunnel piece is plastic the OE was like a cardboard material so just not a good ground material:) Dan's wiring harness should have a ground wire in it to the back of the car. BUT, if not just go local to the light for a body ground.
Rick
Rick Crawford

Don,
I'll look to confirm Rick's observation. If I recall correctly, along with the light wiring, I had three purple wires running out of the rear (2ndary) harness at that point. Dan Masters could not determine what they served unless an early provision for the seat belt warning. Remember my 71 was late in the year.
db
Doug Baker

I seem to recall the following.

3 wires for the tunnel lamp.

One is the power.

One is the ground through the manual switch. It allows the light to work using the manual switch on the light when the doors are closed.

One for the door switches. It runs from the light to the door switches. When the door is closed, the switch is open and no light is on. When the door opens, the switch closes (grounds) and the light comes on. The doors switches are in parallel so either door will turn on the light.

Any other wires would be for seat belt alarms proabably installed after 1970. I don't believe the 69 or 70 had seat belt alarms.

Don't know if this clarifies anything. For more detail I will have to dig out my Haynes if this doesn't help.

Regards
Mike Petryschuk
69 TR6
Michael S. Petryschuk

I just was surprised at the ground being there at all. I was also wondering if the ground connected back in the harness or somehow connect to the body as a ground. Surprised the heck out of me to see that black wire on that thing. It's a good thing I went up to my storage attic to check it out first. Now I've got to run another wire!!!!
DON KELLY

Don
I do not think you need to run another wire for ground. Simply get a short length of black wire and find a local ground from a bolt.
Rick
Rick Crawford

I agree with Rick. Provide a wire so you can screw it in such that it is grounded to the body local to the tunnel lamp.

Regards

Mike Petryschuk.
Michael S. Petryschuk

Don,
Just checked my old harness and ALL the wiring references I have. There are three wires to the tunnel light, a purple one which goes to the light; a purple with a white stripe which goes from the light to the door switch, first left (Driver's) then right. Then there is a black grounding wire. I did not unwrap the wiring harness to ascertain exactly where it goes to ground, but as Rick says, does it really matter so long as it does? There is one black wire going back to the multi-pin junction with the main wiring harness, but there are also a couple of places down stream that it could terminate. There's one section along about the gas tank wiring where three black (ground) wires are all joined together, then I have a black wire going to a terminal (ground) at the Right Rear tail/brake/backup/etc. area. So choose your poison. You got three wires, one in is purple, one out purple/white and one black...ground. The two door switches are grounded to the body where they are screwed in, but the black wire from the light attaches somewhere. I just don't know where and won't until I remove the tape to physically trace out each wire. I don't plan to do that until I'm ready to build the new wiring. Hope this helps.
db
Doug Baker

Doug ,I'm taking all those tail light plus a new fuel pump ground up front to a central grounding bar that will be connected to the battery. I'm just trying to figure out why that light needs a ground in the first place. Isn't the PW wire already act as a ground??
DON KELLY

"Isn't the PW wire already act as a ground??"

The P/W grounds through the door switches; the black is the ground for the manual switch on the light itself.
Dan Masters

Gee thanks Dan, I thought you told me you were too busy to keep up with the forums. Just popped in long enough to make me look foolish.
DON KELLY

Don
Like I said, the tunnel pieces where never metal so where not much good for grounding a circuit. That is why the black GND. wire.
Rick
Rick Crawford

But I don't want to run another ground wire.
DON KELLY

So...?? Do w/o the manual switch. It's kinda like gravity Don...!! You may not like it, but it's the law!! If you want a manual switch, you need to complete the circuit. Take it to ground!! (Look at me, acting like I know beans about electrical circuits):)
db
Doug Baker

I don't know if I should call you Mr. Newton or Mr. Edison!
DON KELLY

Don...just so long as you call me @ Happy Hour:)
db
Doug Baker

Who'd have thunk I could have gotten this many post with a request about a tunnel light?
DON KELLY

The stupid light is as functional as the dash lights.


Quote: "But I don't want to run another ground wire. "
Then don't. But you will need to run a short one locally to give you ground.....if you want to be able to do some sort of contortionist thing and reach around to turn it on to illuminate nothing.
Rick
Rick Crawford

I think I will change the bulb to a 150 watt halogen!I figure that will throw a little light
DON KELLY

From looking at the wiring diagram the tunnel light is controlled by it's ground. Meaning it has a constant positive feed and doesn't have or need a local ground. It gets it's ground from either the door switches or the manual switch to complete the circuit. Connecting this wire to a permanent ground will make the light stay on all the time.

Sylvain
S Demers

Sylvain,
QUOTE:"Connecting this wire to a permanent ground will make the light stay on all the time."
I am not sure what wire you are talking about.
Sylvain, I agree the purple wire is fused 12V and is direct to the tunnel light via the MOLEX connector hidden behind the driver foot well side panel. This is true for the purple/white also. So yes the light does not need a "local" ground at this point if you want the light to come on with the GROUNDED door switches.

BUT, if you want to do what I said in my last post, turn the light on with the switch, then yes you have to run a local ground "from one side of the switch"
(me thinks I was not clear on this point:). Sorry for not being clearer on why the local ground.

Rick
Rick Crawford

I tought you meant to ground the wire locally at the light rather then bring it back to the switch.

Rick as you said the switch will need a local ground. Something that should be simple enough.

But then who I am to say. I had great plans or replacing my wiring harness last winter but never got around to it. Neither did I install my new muffler.

But after this morning the car is ready to go in it current state for another summer, just waiting for warmer weather.

Sylvain


S Demers

My lic. Plate light on the rear bumper(71) did not work and was trash ed when I bought the car. Is there a ground wire to that thing too?
DON KELLY

Sometimes Don not sure if you are asking a real question or just stiring the pot.


To answer your question. There are 2 wires going to the bumper mounted plate light(s). One is Red and is 12V the other is GND and it looks like mine is a dirty red but IS ground. The chrome piece is mounted on a plastic base and for this reason requires a ground wire. The GND wire terminates back at either left or right running lights in a double wired(GND) spade connector.
Rick
Rick Crawford

Rick- I looked at mine up in my storage area and it had been reworked. After I read your post I still am not sure. On mine there are 2 lights and each have 1 wire coming from it. I don't see any ground. But I am with you on the plastic thing and that is why I asked. Do like the "stir the pot" remark. Would i do that?
DON KELLY

Don
Could it be that the mounting bolts are the ground source through the bumper? I wounder this re my last post and the colour of the wires. BUT, why run 2 red wires for both lights...one wire is enough.
Doug B; what are the colours of wires on your harness?
Rick
Rick Crawford

Rick,
I'll look and let y'all know. I'll also check the diagrams to see what it should be:)
db
Doug Baker

Gentlemen, I have my lic plate light in hand and it has one separate red wire too each light. I do believe the ground is through the mounting screws too the bumper.
Joe

http://i165.photobucket.com/albums/u44/Tr6_easyrider/IM000449.jpg
Joe S.

Joe- Your the man thanks. My light looks alot like that but broken in a couple of places. Anyone have a used for sale???
DON KELLY

Thanks Joe. Mystery solved.
Don, I had mine re-chromed. I think it was about $150.00
Rick
Rick Crawford

It will take more than rechroming, Act of god ,I think!!
DON KELLY

This thread was discussed between 23/03/2007 and 06/04/2007

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