[khgeisler]

So…………keep in mind that the analog VDO gauges work off ground. Before totally freaking, I would put a voltmeter on the chassis batteries and recreate the scenario that caused the dip on the gauge.

Your problem with all the lights not working and the wonky gauge could be as simple as a ground circuit.

Newell daisy chained the grounds for the instruments. Bad practice in hindsight. When the ground deteriorates so does the accuracy of the gauge. It is the primary reason that most run VMSPC or some other instrumentation software that takes its signal from the DDEC engine computer.

Richard, I used my 12v test light ground lead to add a ground to the backlight circuit.  At first nothing changed, I removed the test light ground and what do you know, everything was working, even the dimmer.  I do have VMSPS, but I am OCD about things working like they should as a double check.  I will keep looking for the gremlin.  What a wiring nightmare, with ne access.