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Triumph TR6 - Prince of Darkness Strikes Again

My electrical system had a melt down on my 71 TR6. I have no brake lights or turn signals. My wiper motor no longer works and the horn is now silenced. I have searched the local area for someone to work on it. I have had 2 refusals 2 laugh out louds, and 2 guys have looked at it. One gave up and the other says it would cost about $2500 USD. 2 Questions here:

Question 1 Does anyone know of anyone in this general area that could work on it?
Question 2 How much work and what kind of expertise would it take to buy a new wiring harness and install it myself?

Thanks for any input

Don
Don B

Don,
Dan Master's wiring harness is about $325.00 if I recall correctly. You cannot get any better and he or his son is available for technical assistance. Contact Dan and give it a try.

Talk to the other Don here and he can give you some pointers from his experience.
db
Doug Baker

Don- The most problems occur via bad ground.Here is a link to the 71 colored wiring diagram. clean up all grounds and check all the connections. Dan sells a book about the wiring and it is useful.

http://www.advanceautowire.com/tr2506.pdf
DON KELLY

Don,

I second what Don say's. Bad grounds cause most of the problems. With a little patience they are easy to fix. Clean all of the obvious connections that are direct sheet metal connections and then find all of the inline ground conncetions (single socket male and female connectors with rubber sleeve)and clean them.

Is the harness really melted as in "meltdown"? If so, then go with Doug's suggestion.
HP Henry Patterson

First, check your fuses. If your fuses are blowned, replace them and do not continue with this post. If all fuses are good, then I will get you started in the right direction.
Electrical repairs are easy if you just follow the wiring branches to find:
a)if your not getting 12 volts to the circuit.
b)if your individual items (ie: brake lights, turn signal etc)are not working properly.
I think your problem is that your not getting 12 volts to your brake circuit and your horn is just not working. You'll have to go through the circuits to get the answer. All you need is a cheap volt meter to verify if 12 volts is going through your circuits. From here on, refer to the schematic that Don has sent.
On a 71' tr6, brake lights, turn signals, windshield wiper is on the same circuit (branches in your wiring harness). Horn and hazard switch on another. To find the brake light circuit on the schematic that Don has sent, look for the fuse box on the schematic, then look for the 4th fuse on the fuse box. The white(W) wire from the ignition switch brings 12 volts to the circuit. It goes to the fuse box, then is outputed with green (G) wires too 3 areas
1)wiper motor
2brake lights and switch
3)Guage voltage stabilizer, then to the turn signal
flasher
Did you find it?? Ok, next, White (W) wires on a 1971 tr6 is a power feed from the ignition switch and is hot only when the key is in the run position. These wires are not fused until it goes to the fuse box. That being said, check if the White (W) wire has power. (remember to turn on the ignition switch) If it does, your problem is not before the fuse box but after. If you are not getting power, your problem is at or before the ignition switch. Continue this process until you find were you are not getting 12 volts, then repair problem.
Horn circuit is the 3rd fuse on the schematic. Being that your hazard switch is in the same circuit, check if it works. If it does, you have a issue of no power going to the circuit. If it does work, your problem may be in the horn circuit. Do the same fault finding procedure as with the other circuit.
This should get you started.
Good luck and post your results
Benji
benji

Sorry that I screwed up my listing. Let me clarify troubleshooting the horn circuit, if the hazard switch doesn't work, you don't have 12 volts going to the circuit. If it does work, you problem could be in the horn circuit only.
benji

Thanks for all the input guys. YES the wiring harness did melt together. It melted along the chasis next to the drivers seat. It smoked pretty good. I am not sure how far up it melted

It would seem that getting a whole new wiring harness would be the best approach. I am thinking I will follow Doug's advice and get one. How do I contact Dan?

Thanks
Don B

Don,

I had a little meltdown too but I was able to patch it back together.

The original system has wires that run directly from the battery un-fused going through the dash and powering many of the dash items.. again un-fused. The fuse box on the other side of the engine compartment is at the end of some of those long unfused wires coming from the battery. So they don't do much good if there is some kind of short between the fuse box and the battery. So that's how we get meltdowns. I'm sure Dan Masters harnesses are properly fused close to the battery and I'm sure he used relay's to swith the high current stuff like headlights. So replacing with a modern designed harness like his is the right way to go. The harness you describe powers the rear of the car. It's likely you'll need the front harness as well.

Good luck and let us know how it goes.
HP Henry Patterson

I guess your tr6 summer is over thanks to Prince Lucas!! Been there done that! I know how it feels...
benji

Don,
I have Dan's wiring harness in hand, but due to other issues won't be installing it for some time yet. Let us know how the rewiring goes. All of us can learn from your experience. Tap in to Don Kelly's experience. He's still wiring his -6!!

Check the archives here for Dan Master's Web site. I just don't remember it and am on a new computer so don't have it in my favoriities on this machine.
db
Doug Baker

Don
The location of your meltdown says only the rear wiring harness needs replacing. The rear wiring harness starts at a white connector(MOLEX brand) behind the driver outside foot well panel.

HOWEVER, you mention other items like horn and wipers also not working which obviously do not have connections to the rear of the car.

I agree that it sounds like a new wiring harness is in order. I also agree that Dan Masters harness is best choice.

Replacing the wiring harness is NOT a simple task. It is definitely an entire winter project. Dan's harness comes with good instructions but be aware it is a fuse block with a lot of wires coming off of it and you have to "build" the harness yourself. This is NOT a job for an inexperienced person. The entire dash has to be pulled.
Sorry Don but someone had to tell you this is not an easy job.
Rick

Dan's WEB site.

http://www.advanceautowire.com/
Rick Crawford

"Tap in to Don Kelly's experience. He's still wiring his -6!!"

Hey,it's basically done. Waiting on the electric tach to come back and then the dash goes in. Hopefully my tach didn't end up in the Missouri River or was that the Mississippi River.
DON KELLY

Don B,

Yes it is a difficult job but as you mentioned one person won't touch it and another want's $2500.00. Doesn't leave you with many choices.

You maybe can get away with replacing only the rear harness but definately the front will need some attention. Even though the rear harness experienced the meltdown it still pulled high current through the main front harness which of course feeds the rear harness so the front will at least need to be inspected for melted wires. Some main harness wiring could have melted even though the smoke came from the rear harness.

If you are mechanically inclined you should be able to do the job. If you are mechanically and electrically inclined then you will be able to do it. It will require patience and good organization like labelling things as they come apart.
If you aren't too mechanically inclined then if you have a new harness in hand you may be able to find someone to install it for a lot less than $2500.00.

Back to Dan Masters. I think you can talk to him directly and get a feel for the job. I hear he is very good at coaching people along. Also, he can probably help you determine what caused the short in the first place. So, as Doug say's find Dan's web site and get in touch with him. You'll at least be able to determine if you should do it yourself or not.

You could alway's tow the car to Don Kelly's big garage and hang out with him to fix it.
HP Henry Patterson

Guys

I went to Dan's website and downloaded his manual.

I took a little time today to pull apart the wiring harness. It appears that a solid purple wire melted down from just below the dash to just behind the drivers seat. The cover melted completely off but it does not appear to have damaged any of the other wires. I will try to spend some time later to trace the wire.

I was talking with a friend and we have a vocational school nearby with an large auto mechanics program. I may call to see if they are interested in a project for electrical systems. I figure it can't hurt to ask.

I will keep the board posted on progress. Thanks to everyone for their invaluable information.

Don
Don B

Don,if I recall correctly, that purple wire is either going to the seat belt warning buzzer (not installed on the 71, but may be wired for it) or the interior light. If the latter, it's grounded at the junction box inside the left panel on the driver's side, or at the interlock at each of the doors. You may have lost a ground or ?? Dan will likely be able to tell you what went wrong given accurate symtoms. Dan has another box than what you downloaded about "fixing" wiring problems. I'd recommend that you get that book too.
db
Doug Baker

Doug- Don't forget it also feeds the boot lamp.Here is my version of the boot lamp.I have one on both ends of the boards.

DON KELLY

Don,
The rear wiring harness feed the boot lamp, but the purple wires go to the tunnel light, do they not?
db
Doug Baker

they should then go thru a 4 port connector and travel on to the boot to feed the power for the boot light.
DON KELLY

Purple wires recieves 12volts from the Starter which is hooked directly to the battery with a brown wire. This brown wire is a major power feed which is also wired directly to the ammeter. This means that the brown wire is NOT FUSED!! Does the ammeter work?
From the fuse box, a NON FUSED brown wire goes to a fuse, then outputed with 2 purple wires (now fused) that branches fused 12volts too:
1)Horn: We already know that's been affected.
2)Glove box switch
3)Tranny Tunnel lamp
4)ignition key warning switch
5)Hazard switch
6)Trunk light
Check these 6 items to verify if they still work.
Your brake lights and turn signal are on a different circuit which tells me that your meltdown probably damaged that branch of wires.
I think the root of you problem may have come from the unfused brown power wire. This branch of wire has 2 places I would look at.
1)From the starter to the ammeter. (also look at the
back of the ammeter to see if the 2 hot contacts
shorted out your system.)
2)On the driver's side inner fender panel, just in
front of the fuse box, there is a whitish plastic 4
way connector. Check:
a)the brown wire from the starter.
b)the brown wire going to the fuse box.

benji

Doug et all
"The rear wiring harness feed the boot lamp, but the purple wires go to the tunnel light, do they not?"
This entire statement is true. The purple wire feeds both and the door switches along with the ignition key warning circuit and illumination lamp just under the dash. As I have mentioned, this connector (MOLEX connector) behind the driver L side kick panel has this purple wire along with a red wire (rear running lights), a green/white (R turn), a green/red (L turn), a green/ purple (bakes), and a green/brown (reverse). These are the only 6 colours going to the rear of the car In Dan,s wiring schematics, the circle with the X in it is the MOLEX connector. It appears Dan changes this symbol to a "]" for the GREEN/X wires. These are all 100% fused circuits at the fuse block. This information is straight off Dan's schematic. There is NO grounding done at the MOLEX connector. All wiring going through the MOLEX connector are the + side of 12 volts.
I agree the big brown wire under the dash is a potential for melt down. I have said many times in the past that the Dash light dimmer switch ( a potentiometer) should be by-passed as it is also a fire hazard.
Don B, I have no answer why the purple melted down from just below the dash. The best answer I have is that the purple wire grounded out and that possibly the fuse is too big. remember a 35AMP fuse in NA is not the same as a fuse in the UK. The NA fuse has a much higher AMP load rating.
Check the wires going over to the tunnel lamp.
Good luck Don B
Rick
Rick Crawford

To help clarify Rick's comment, there is 3 separate big brown wires that are not fused. They are:
1)From the starter to the ammeter.
2)From the starter to the whitish plastic 4 way
connector. (located on the driver's side inner
fender panel, just in front of the fuse box.)
3)From the whitish plastic 4 way connector (located on
the driver's side inner fender panel,just in front
of the fuse box) to the fuse box.
The brown wire that Rick is referring to is the 2nd one described above. This big brown wire from the starter to the whitish plastic 4 way connector is neatly wrapped up with other wires in the front wiring harness. When that big brown wire melts, it melts the protective wiring cover off the other wires that are wrapped in the harness. Specifically, the purple wire from the fuse box to the horn relay is probably the wire that melted with the big brown wire in the wiring harness. This purple wire is part of the curcuit that has the Horn, Glove box switch, Tranny Tunnel lamp, ignition key warning switch,Hazard switch,and Trunk light.
benji

Benji
It looks like we are talking about 2 different connectors. The whitish one you refer to ( on front left inner fender in front of fuse block) indeed is unfused and is heavier gauge brown wires. It is depicted in the schematic just above the ammeter ( a rectangle with 4 circles inside). I do not have the Brown/red wire in my car and I think the lack of this wire is the norm. I have always wondered the real purpose of this connector as the connection is straight through it.

The connector I refer to is inside the driver compartment behind the left side driver kick panel. It is made by a company called MOLEX and just happens to also be white in colour. There is no brown wire at this connector. The MOLEX connector connects the front wire harness to the rear harness.
Rick Crawford

Yes, we are talking about 2 different connectors. Here is a picture of the whitish plastic 4 way connector block located on the driver's side inner
fender panel, it's between the fuse box and silver colored solenoid. These were used on 69' - 71' models only.


benji

Benji
Mine is a little dirtier looking than that one. I also see it only has the 2 brown wires.
This is not your car....I know yours is green.
Rick
Rick Crawford

Rick,
Color is safron yellow.
here's an image to clarify.
Don B,
How it goin'?? Did you find the root of your problem?
benji

Let's try that again...

benji

OOPS my mistake.
You have the british flag under the bonnet...yes?
Rick
Rick Crawford

Well I spend several hours trying to trace the wires back and had some progress. However, in a case of Murphy's Law I must have knocked a wire loose because now I cannot get the car to start. It turns over fine but will not catch. ARGGH

I am going on vacation to see the Grandkiddies so I will try to tackle this after vacation ALAS
Don B

This thread was discussed between 04/08/2007 and 20/08/2007

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