TR6 Dash light issues

[ichthos]

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?

 

[Gliderman8]

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.

 

[RGK]

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?

 

[DrEntropy]

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.

 

[Jerryny]

Here's a link to TR6 wiring diagrams
TR6 Wiring Diagrams

 

[poolboy]

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

 

[ichthos]

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?

 

[ichthos]

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?

 

[RGK]

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.

 

[RGK]

Can anyone identify this, it is hanging from the dash left side of steering wheel. Voltage stabilizer?

 

[poolboy]

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

 

[RGK]

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.

 

[poolboy]

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

 

[RGK]

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.

 

[RGK]

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.

 

[Gliderman8]

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.

 

[RGK]

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.

 

[Gliderman8]

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.

 

[ichthos]

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.

 

[Tr6easyrider]

When I reskinned my dash, I didn't see a need for it..