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TR6 Dash light issues

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I

ichthos

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Been a while since I have been here, but it is good to be back. My first TR6 was crushed by a tree, but I was able to find another 69 TR6 just a few serial numbers away. I have been busy transferring parts from it to my “new” TR6 As needed. I presently have no dash lights. I have had my hands up in the wiring as I had to change out two gauges, but I cannot find any wires that are disconnected. My first thought was it is a grounding issue, but the ignition light, wiper, and washer work. None of the gauge lights work. I checked the fuses under the hood too. Any thoughts on how to proceed?
 
Have to ask... Have you check the status of the bulbs to make sure they are working? Also, you should make sure the base of the bulb holder is making a good ground.
Lastly, does your car have the rheostat for dimming the bulbs? You might check that to make sure it is also working.
 
Having the same issue, but have not started trouble shooting yet. Will probably start on it this weekend and post if I find something. Do you have a wiring diagram?
 
Are the parking/headlamps working? If not, voltage supply at the switch (should be a solid brown or blue wire, constant 12V, not ignition dependent) needs checking. If so, then the switch and/or connection to rheostat, or rheostat itself could be the problem. A VOM or 12V test light would be needed for "chasing electrons" through the system. Instrument lighting will be solid red for voltage in, red with a white tracer from rheostat to bulbs. Headlamps will have solid blue for voltage in, blue/white for high beam, blue/red for low from dimmer switch. Black is ground in all cases.

All that is dependent on there being original wiring, not someone being "creative" in the past, IYSWIM.
 
Have you checked the connection at the grounding spade for the dash ?....It's in the engine compartment between the battery and where the heater hoses enter the firewall
 
Thanks for the suggestions. So, here is my progress. I checked the ground to the car and cleaned it. When I first got this car I switched most of them to LEDs, so I am pretty sure they are good. My headlights, rear lights, marker lights, and turn signals work. The turn signal and ignition bulbs come on. The dash lights were working when I first bought it, but it has been sitting for a year. Is There a way to bypass the rheostat to see if it is the culprit?
 
So, trying to get at the rheostat. I was going to try just connecting the rheostat wires, but i can’t even get my hand in there. is there a trick to getting at this to remove the wires?
 
My understanding is you go in from the passenger side. I will be trying this weekend with a test light which should be easier than getting my hands in there. I am almost certain the rheostat is the culprit. It can be cleaned or bypassed. Dan Masters 'Electrical Maintenance Handbook' is an excellent reference, well worth the money.
 
Can anyone identify this, it is hanging from the dash left side of steering wheel. Voltage stabilizer?

P1020212RS.JPG
 
Looks like one..TR6 has it attached and grounded to the speedometer housing....not hanging loose
2 green G wires on the B terminal and a lite green LG to the temp gauge on the I terminal
 
So if it is just hanging, it is not grounded, which would affect anything connected to it? My temp gauge does not move with engine temp.
 
Yeah the wiring schematic shows it's grounded by attaching it to the speedometer case which is also grounded
I suppose you could just test it by attaching a jumper wire from the stabilizer case to a good ground.
Be sure to check the ground connection on that tab I mentioned earlier that's in the engine compartment
Credit to Jim Herter for the original picture
TRIUMPH CABIN GROUND 001.JPG
 
I had checked that ground, it had been painted over so I dremeled it shiny. I will ground it to the headlight dipper with a jumper and see what happens.

No change with the jumper. All dash lights, wipers, turn and hazard lights out. I will start checking connectors from the fuse box tomorrow.
 
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For icthos; from the passenger well the red & R/W. I would have to remove the radio to get my hand up there, might be able to take the rheostat out from the front if there is enough slack, but have a feeling there is no power to it.

P1020222RS.JPG
 
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I just by passed my rheostat about a month ago. I removed the passenger footwell speaker panel, as well as the rheostat knob and screws holding the rheostat in place. With some patience I was able to remove the three wires on the rheostat. I made a three-wire connector to hook them together.
IMG_5036 2.jpg
 
That is good to hear the rheostat does come out the front. I want to make sure there is power coming into it before taking it out. I have a few confusing electrical issues going on.
 
No, the rheostat does not come out of the front. I removed the screws and pushed it into the dash and then I was able to remove the wires.
When I was done I pushed the rheostat back into the hole and reinstalled the screws.
 
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Well, it was the rheostat. This is my third TR6, and I never had one fail before. I temporarily connected the wires. Once I get everything working, I have to replace the horrible dash, and then I will just replace it with my spare. Thanks again for all your help.
 
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