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Discussion Starter #1
I first noticed that my amp gage (converted to a volt gage) was showing no charge, it was pegged to the extreme left. On investigation, I discovered that the turn signals, shift indicator light in the console, radio and air conditioner compressor also did not have power. I've looked over schematics but just don't see a connection to these devices. A/C fan motor runs, headlights work, all other gages work, interior lights works, etc.

What is the connection between the above devices/bulbs that could be causing this problem?
 

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It seems that you have several distinct circuits that are suspects. I suggest starting with the simple things and proceed methodically. It is usually a process of elimination.
Visually inspect the wiring and connector plugs. Any damaged wires or dirty connections? Trace the circuits from power source. Are you getting power to the ignition switch (unfused)? Are you getting power at the headlight switch? How about the turn signal switch? (Does the horn work?)
Chassis grounds? Are the battery terminals clean and tight? Is the engine block grounded to the firewall? Are the underdash grounds all clean and tight?
Are the fuses and connections within the fuse block clean and solid? Are the light sockets clean and tight? Are the sockets grounded? Do you have the correct bulbs and do the bulbs work? Is the main firewall electrical plug (Near the left side hood hinge) clean and tight?
At this point tracing individual circuits may be necessary. For example, does the thermostat switch inside the A/C evaporator have power to one terminal when the A/C fan switch is "on" and Max A/C is selected? If so, is there power at the other terminal of that switch? If so, is the pin switch on the A/C control switch (defroster flap above the cigarette lighter) have power to one terminal? If so, is there power at the other terminal? If so, is the compressor power wire coming out of the firewall inside the engine compartment hot? If so, is the connector at the compressor clutch getting power? If all of the above are "yes" and the compressor clutch is still not working, jump the battery to the compressor clutch briefly and listen for the click. If no click, the clutch is the likely problem.

Hopefully this makes sense. A DVM might come in handy to narrow down the defective parts of the malfunctioning circuits. A wiring diagram can be found on line if you do not already have the Factory Service Manual.

Good Luck.
 

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Discussion Starter #3
Thanks for your words. It's a totally rewired car, new harness. I think that sometimes this sort of work leads to problems. I realize that I will have to trace individual circuits - not fun either! After reviewing the wiring diagrams, I could not find a common point past the battery. I hoped that someone would have a magic answer, you know, the one that takes 2 minutes to fix instead of potentially dealing with hours of diagnosis. Thanks for the encouragement, I'll be digging in this evening.
 

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Thanks for your words. It's a totally rewired car, new harness. I think that sometimes this sort of work leads to problems. I realize that I will have to trace individual circuits - not fun either! After reviewing the wiring diagrams, I could not find a common point past the battery. I hoped that someone would have a magic answer, you know, the one that takes 2 minutes to fix instead of potentially dealing with hours of diagnosis. Thanks for the encouragement, I'll be digging in this evening.
"Rewired" meaning STOCK harness or.....? All those non-operational things you mentioned run through the ignition switch so I'd start looking from there outward.
 

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Discussion Starter #5
Stock, yes. Nothing funny added to the car, no post production design changes. Ignition switch was my thought also. Thanks.
 

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There should be no connection between the voltmeter and any other gauge. Likewise, the lights should have nothing to do with any gauge.

I suggest whoever installed the harness did it badly. Start over. The stock harness had no provision for a voltmeter, but did have provision for a passive ammeter. Start with that.
 

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You're familiar with checking a fuse with a volunteer, you put the meter across the fuse if you have power from either side of the fuse to ground you have battery voltage up to that point. If you get battery voltage on one side and not the other you have a blown fuse. If you now put the meter across the fuse you will read the full battery voltage no matter what.

When you test with a voltmeter going across a connection or something such as going across both contacts on a bulb and you read full battery voltage that is open and the problem. Anything less, it's ok. That means you're seeing the voltage that device is using.
 
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