My cheap circuit tester barely lights up at my ash tray light, when the headlights are off. I believe I have a current leak on the illumination circuit. I noticed my aftermarket gauges no longer dimmed when I turned the lights on. I had tapped the ashtray light for the gauges, and hence my investigation.

Do I have a bad relay or switch?

 

It sounds to me like more of a grounding problem, the test bulb shouldn't light even a little bit in that circumstance.

If it's a relay, it would either work or not, if it's a switch, it would affect the whole circuit, not part of it.

Look for any wrapped or exposed wires that may be touching and go from there. Maybe check what was previously done and resolder / clamp any custom connections.

 

Thanks, I'll check if the ground is back feeding. Something is definitely strange.

 

Edit:

I am also getting unexpected current at the glove box light, when the ignition is on. Both the ashtray light and glovebox light grab power from the TNS relay, via the dash hardness and the joint boxes. At this point I think it's either a short in the dash harness or a leaky TNS relay.






I don't really love electrical stuff, but now that we're here...

 

There is a dash brightness adjustment to the right of the steering wheel. Does changing that change the brightness of the gauge? Go all the way up and down, I know there's an illumination wire you can tap into that works but is backwards - when the dash lights are bright, the gauge will be dark and vice versa.

Dale

 

Hey Dale, it does not make an effect. The issue is the Defi gauges have an illumination wire, which dims the Defi gauges when ON. Since the gauges detect this micro current, they are always dim.

I could work around this pretty easy (for now I yanked the connection, and the gauges are bright again), but I want to make sure I didn't screw something up with anything I did and there's no larger issue.

I had made a harness to set these gauges up, and i've ripped it out and nothing change. So far still looking at TNS relay or harness short. I do have some mysterious radio issues I had chalked up to the old stock head unit, also. So, there might be something here.