I'm almost completely finished with my 1981 Z28 restoration, but noticed some issues yesterday that I can't quite troubleshoot... First off, I noticed the turning signal fuse was blown, replaced it and everytime I turned them on, it fried, upped it from a 20a to a 30a just to check, and it no longer burned up, but definitely not right... I noticed yesterday when using the turning signals, when turning right, the light wouldn't flash on the gauge panel, and the gauges would jump up and down when the right turning signal is used... Last night was the first time I tried all the lights and took it for a spin... First off, none of the right half of the lights on the gauge panel are working, and when I turn on the headlights, they'll light up fine for about 4 seconds, then they start flashing, definitely weird... Maybe a bad printed circuit?... Any ideas what might be causing these issues?... I did restore the gauge panel, repainted all the needles, replaced all the bulbs, polished the lens, and can't say that I saw anything out of the ordinary... Any help would be GREATLY appreciated...lol

 

Sounds like the turn signal circuit is shorting through the gauge circuit. Id inspect the circuit sheet and the connectors. Something is probably fried back there. Oh and switching to a larger fuse is never a good idea. All your doing is magnifying the problem at the source. Let us know what you find.

 

So you're thinking that it's definitely on the back of the gauge panel somewhere, correct?... I had already replaced the turn signal switch in the column due to a couple ripped wires at the connector, so I'm guessing that would leave the issue solely at the back of the cluster, correct?... Not exactly an electrical genius by any means, so please bare with me...lol

 

Im not either by any means but it sounds to me that it would be going on behind the dash.

 

I would agree, so probably the printed circuit would be the culprit I would imagine... Anyone happen to have a good 81 Z28 printed circuit lying around they could live without?...lol

 

May very well be that the two issues are connected, but it might also be that the short simply pulls voltage down, and creates the issue with gauges fluctuating. Need to keep an eye on the voltage while running the right turn signal, and see if it's fluctuating a lot when used.
If you don't have any issues in the dash when turning on the headlights, or tapping the brakes, then the issue is ahead of the wiring going to the back of the car. Might be a problem inside the column, or under the dash. These things can be a real headache to diagnose and track down. Might look over the wrapped harnesses to see if there's any bare spots, or hot looking spots. Might even have to strip the black wrap to view the wires, and re-wrap it later.

 

If you have a short (a path directly to ground), all your power will take that path since it is the path of least resistance. You may want to start pulling things (disconnecting) to take it out of the equation. Good luck, electrical gremlins can be a pain in the behind to find.

 

Sweet, thanks a lot for the input fellas, I guess I'll start with the printed circuit just to eliminate it, and while I have the gauges out, I can give the harnesses to good look over for any visual signs of wear or bear wires, at least this will be a good start...

 

Does anyone have any idea what years of printed circuits all work for the 81 model w/gauges, I've read that all 70-81 w/gauges are the same, can anyone verify this?...

 

There are just two types that i know of. One for the dashes with gauges and one for the dashes with warning lights.