View Full Version : TR6 TR6 electrical problem continue

05-21-2007, 07:43 PM
Ok I am the one who pulled the facia out to reveeneer it, and the problems began, when I put every thing back, no turn signals, no heater blower, brake lights, the oil pressure gauge read low but since check with store bought gauge and Oil pressure is ok, I now have realized that DPO's have really screw the wiring up. jumpers every where,wires cut and taped, no hazzard switch, no brake pressure warning lights, no washer pump.no glove box light no reverse lamps. now I can and will probably just jump wires to get everything working well brake lights only dont care about hazzard or brake warninglamps, my bigest problem now is the car wont quit running with the ignition switch off, however once the voltage stabilizer wires are hooked up if I switch the ign off and turn on the fan or turn signals the car will cut off, which I think means when you turn the IGN switch off it goes to ground and kills the coil and the engine stops. I guess I will and need to buy a complete wiring harness and rewire, I am crying now but I dont want to do it till the winter. So the question is, Dan Masters wiring harness? Original harness and How difficult is it to install

05-21-2007, 07:56 PM
The ignition switch does not ground the circuit, it just cuts the power to it. You must have something else feeding power into the ignition circuit, but only a little bit, enough to power just the coil but not the coil plus fan or turn signals. That likely also means it will run the battery down. Does your alternator light work ?

Dan's wiring harness is nowhere close to original; it's a significant upgrade with high temp wires, lots of fuses, and relays for most common additions. Probably no harder to install than an original harness, though. And definitely high quality.

05-21-2007, 08:38 PM
My TR6 had a front wiring harness that was toast. The rear harness was still good so I replaced the front harness with an origional style from British Wiring. No doubt Dan Masters harness is an upgrade. I just like the look of the origional. It came pretaped with all the bulb holders and connections installed. They must tape it on a jig because were there is supposed to be a turn in the harness it's already there. Out of all the bulb holders there were only 2 or 3 that I had to salvage from the origional and the Ignition switch connections were different. Found out in 73 they had several different style connections there. If you go that way, don't do what I did and tear out all the wires before you get the new harness. They say to cut the wires a few inches back from their destination to make it easier to identify which wire goes where. I was too impatient for that and had to learn the hard way. Definately get Dan Masters electrical maintenance book. It was invaluable and made the job so much easier. Phil

05-21-2007, 08:57 PM
My alternator light does work but I have noticed that sometimes when switching wires around and its always the same 3 green wires is the alt light glows bright when on and dim when switched off, and when I ground it the alt light goes off and the engine stops, I think I will at this point cut the sheathing off the harness and pull green wires to each terminal that I am having trouble with and see what happens. I do agree somewhere power if feeding back to the IG circuit, it shouldnt based on the diagram so what did the DPO do??

05-22-2007, 12:45 AM
I feel your pain. After I bought my car I spend weekends contorted under the dash trying to find out what was going on with the wiring. I studied the service manual wiring diagram and sorted it out wire by wire. I had oil lights flashing when I turned on the indicators, oil pressure light coming on when I turned on the interior light switch, missing green wires, etc, etc. I still have some 'extra lights' floating around under the dash that don't seem to fit in with any of the wiring diagrams, but I have everything else working as it should.

05-22-2007, 08:53 AM
https://www.britishcarforum.com/bcforum/u...true#Post244580 (https://www.britishcarforum.com/bcforum/ubbthreads.php?ubb=showflat&Board=5&Number=244580&Searchpage=1&Main=26326&Words=self+inflicted+wound&topic=0&Search=true#Post244580)
I had most of the same issues your having except I added a new ignition switch at the same time. Once the BCF guys got me straight on that, I very dilibretly went through and cleaned and checked all connections, finding a bad one in my turn signals, and a crossed wire on the hazard switch.
I found using Dan Masters wiring diagram more usefull than the Bently as it is printed backwards. Once I found the 2 mistakes- all works well.

05-22-2007, 09:21 AM
Getting more bizzare, I took all the black tape off harness under dash, chased wires, crank car turn off ign car keeps running, measure voltage on white wire at ING switch that goes to IGN lamp and there is 8 volts and light glows dim, now un plug white wire or unscrew Ign lamp, or pull plug from alternator and the car stops, Could it be a bad alternator? its a bosch 55 amp unit and its 6 months old

05-22-2007, 09:52 AM
Yes it is possible. I cannot find the posts in the archives on the problem I had with my car not shutting off. I wired the ignition switch wrong, and once corrected solved my problem, but I do recall someone chiming in on the possibility of a bad alternator. As an amatuer Tinster I have know way of telling you how to check. Maybe someone else knows?

Geo Hahn
05-22-2007, 10:31 AM
Just a SWAG... but when something that is switched off is still getting some power -- I'd be thinking 'Bad Ground'.

Usually I've seen it happen on lights where the absence of a good ground causes the circuit to seek a ground by passing back (via a bulb filament) thru the hot side of a switched off circuit, thus introducing some current to something that should be off.

I've said it before -- a new harness on the '3 was one of the nicest things I ever did for myself.

05-22-2007, 12:01 PM
My memory on this is really poor but I seem to recall some discussion of a bad diode in the alternator / regulator leading to some strange problems. The bad diode allowed some current to flow through the alternator circuit even when the ignition was off. I think the result was that the 'ignition' light would be on when the car was switched off and that the car would tend to keep running when switched off. I think this became a recognized problem and eventually a change was made to the circuit so that this failure wouldn't result in a car that would just keep running. Does anyone else remember this or am I just imagining?


05-22-2007, 01:20 PM
Easiest way, after you open the hood, car parked in neutral, brake on, engine still running, just reach in and unplug the connector on the back of the alternator.

05-23-2007, 05:20 AM
Well I pulled the Alternator off and had it checked and they said there was nothing wrong with the Alternator, I put a new switch in also, and hooked the wirs up the same way and it appears to be right by the diagram, I did try swithing the white wire to the alt around to another position on the switch and it will shut off but its not by the diagram, Still stumped.

I am thinking about a new harness but scared I would get in over my head

05-23-2007, 07:09 AM

I could barely install a ceiling fan when Wendy bought
the TR6. No automotive wire experience at all.

DPO Pedro had my wiring so screwed up I had to gut
every wire in the car and start over. PDO Pedro had
replaced all the dash wires with K-Mart black wires
and then wrapped the entire mess with black electircal
tape. And nothing in the dash functioned.

I had no color coded wires to trace and none of the
interior or exterior lights on the car functioned.
The engine turned over and that was about it from an
electrical standpoint.

I purchased the Dan Master Power block wire harness and
100% every light new from TRF. At Mike Masters instructions,
I removed every existing wire in the car prior to installing
his new wire harnesss. I installed the new using Dan's
install booklet guide and wire diagram.

I never could figure out the fancy electrical gizzo meter
boxes. I installed the new wire harness system with only
a lightbulb attached to two alligator clips. Dan and Mike
helped me every step of the way.

Everything electical now functions on my car.
I say buy the new wire harness and have peace of mind.


05-23-2007, 10:53 AM
Hondo, I feel your pain, as I have been there before. The connections I found that were bad were the female parts of the bullet connectors. They seemed like they were ok, but were not. I clipped them off , went to auto zone and bought male and female spade connectors and bingo, all worked.
Double check that you did not bump any wires on the ignition switch and they are all clean and tight.

05-23-2007, 04:11 PM
I will on Friday I hope to get this mess straightened out so I can cruse this weekend, and the wiring harness will be forth comming. maybe a winter project

05-23-2007, 07:30 PM
hondo, when you get ready to put in the new system remove the tunnel support, the steering wheel and the seats, it will save your back. This makes it easier to get the gauges out and hang a light on the side you are not working on. Give me a yell if you run into trouble, I just live in Salisbury.


05-25-2007, 07:30 AM
thanks Wayne, I have figured out that somehow current is getting to the alt field and the alt is putting out current when the engine is switched off and thats why the car still runs, now how is the question

05-25-2007, 08:33 AM
Did you have the alternator apart?? We ran into this with a rebuilt just last week. The wire that connects inside the alternator for the indicator light was plugged onto the wrong spade of the rectifier assembly thereby back feeding to the ignition circuit.

05-25-2007, 11:18 AM
I didnt take the alt apart so I would assume its not that, besides it shut off ok till I took all the gauges out and the problem started when I put them back in and hooked them up, the amp gauge is the only think that is power all the time and on small wire goes to the Ign switch but there is no way to hook the amp gaues up incorrectly, there is only one place the small wire can go???????

05-26-2007, 10:47 AM
Well everything is back together, new vaneered dash, crash pad, new windshield. the car sill will not cut off when switched off so now I am turning on the fan to kill the motor, who knows maybe the problem will disappear as magically as it appeared. any way Its driving time not rewiring time

01-03-2012, 10:27 PM
I did the same thing, I took off the old dash and put on a new one. When taking off the old one I made a wiring diagram and took pictures of the gauges, but forgot to take a picture of the speedometer and flasher. When I put it back together I used the Bentley manual and a wiring diagram. Car started great and ran great; however, the windshield washer doesn't work, the fuel gauge doesn't work, and the ampmeter gauge is reading backword. I think that I may have put the wrong green wire on the wrong connection on the voltage stabilizer (back of speedometer) as the windsheild washer wires were not hooked up previously and they carry a couple of the same colored wires that hook up to the stabilizer. Any suggestions out there to fix properly? Thanks in advance, as I really don't want to tear the new dash out again!

01-04-2012, 11:04 AM
I rewired the car last fall so all is good now.

01-05-2012, 02:58 PM
I thought that I dropped into a time warp when I was re-reading this thread until I looked at the original posting dates.

01-06-2012, 08:02 PM
Ifuller, funny how the book tells you to hook up the AMP gauge backwards, a throw back to positive ground is my guess. Just reverse the wires on that. The windshield washer should have a good 12 volts, check that it works from the battery, (straigth wire) get the positive side right or it tends to light up.
As for the fuel gauge, you can stick a hot wire to the green/color?? side and see if goes up, good place to start.