69 Console gauge lights on with ignition acc/off/on, but off in run or start

[dahnn]

Hello,

I purchased a second 69 (original SS/RS 350 4 spd convertible) about a year ago and have been fixing little issues.  One thing I have not looked at yet and hoping someone may have encountered before and have insight into the place for me to look:

With the parking or headlights on, the console gauge lights are on with the ignition switch in the acc., off, and on positions, but go off in the run and start positions.

Since the lights work in some ignition switch positions it does not appear to be a ground issue, so I am gong to start looking for a short or other cause.

If anyone has encountered a similar situation I would appreciate hearing what a potential cause/fix for the same condition might be.

Thanks,

Dave

[william]

Camaros built with special instrumentation used a different headlamp switch with a larger rheostat. Possible the switch was replaced or the car was not built with console gauges and still has the standard production switch.

[dahnn]

Thanks for the response William!

I will try to check that out, though not sure why the ignition switch position would matter to the light switch - looks like they would either work or not.  This one is also a RS which from a quick check, may be harder to find a console gauge switch for.  I got it from the second owner who had it since 1977 and said they were original, and the tach is in a correct carrier for a tach (versus a modified standard carrier) but that could have been changed.

I did not know the switches were different and the other 69 I've had since 1974 and modified many time (back in the day when we would swap engines anytime we could get a bigger one, etc.), has been running factory gauges and tach (from a junkyard) since 75, when I also dropped in a 396 and TH400 from a 70 Chevelle 396 SS, without any issues with any of the lights.

[dahnn]

Turns out that the ground to the rear console gauge mounting plate was not providing the correct ground, so a quick jumper solved the temp gauge and console lights issue and also got the fuel gauge to move.

Now the issue is I need to track down issue for constant full reading.

[169INDY]

Constant Full or way past full generally means a bad ground or excessive resistance in the circuit. Fuel Meter

I tend to concentrate at the back of the car First when troubleshooting a Fuel-Gauge Issue.

Assembly Manual Ref: UPC 8 /B5 Sheet 127

Recommendations:
a) Always first Check the Ground Lug of the Sender near the passenger Tire underbody. Clean mating surface, clean terminal spade, Sheetmetal screw tightness, Wire (Black) to Terminal barrel crimp condition, wire soundness.

b) Using a VOM (Volt-Ohm-Meter) on the Ohms scale, Disconnect the Tan or Brown-ish wire terminal in the trunk that is "from" the sender to the rear harness. Connect one meter lead to ground on the body, other lead to the metal of the  terminal going to the Sender, you "SHOULD" expect to ready anywhere from Zero to Ninety OHMs. If Greater than say 100+ or infinity, your challenge is in this part of the circuit.

c) (*Not as fun and not as likely) Check the Fuel Sender Tan Wire 90 degree connector plug located on top of tank