Replaced the dash harness in a 65 with factory gauges and factory air conditioning, now the charging system doesn't work. This car didn't come from GM with these gauges, someone added them. We replaced the harness because it was damaged at the fuse panel and had some butched up wires.
How can I tell if the car has the correct forward lamp harness in it? I had to swap that out on my 70 Monte Carlo to get the factory gauges to work after installing factory gauges, just wonder if this is the same deal.
The amp guage is "stuck" on high charge but a voltmeter indicates no charge.

Also, the tach works intermittenly. Only two wires to the tach? B+ and the other lead goes to the negative side of the ignition coil?

Any help is greatly appreciated.

Replaced the dash harness in a 65 with factory gauges and factory air conditioning, now the charging system doesn't work.
Externally voltage regulator (factory) or has it been converted to a internally regulated alternator? To troubleshoot a externally voltage regulated system, see my posts here http://www.chevelles.com/forums/showthread.php?t=99289

This car didn't come from GM with these gauges, someone added them. We replaced the harness because it was damaged at the fuse panel and had some butched up wires.
How can I tell if the car has the correct forward lamp harness in it? I had to swap that out on my 70 Monte Carlo to get the factory gauges to work after installing factory gauges, just wonder if this is the same deal.
For 65, the differences are in the engine harness, the only major difference is the 2 added wires for the amp gauge.

The amp gauge is "stuck" on high charge but a voltmeter indicates no charge.

Someone may have it wires wrong, amp gauge has 2 leads, one goes to the 4 way splice by the horn relay, the other goes to the junction block on the rad support by the battery. See where the amp gauge wires go to and post back.

Also, the tach works intermittently. Only two wires to the tach? B+ and the other lead goes to the negative side of the ignition coil?

Any help is greatly appreciated. Correct. The case should be the ground, you may want to add a wire to ground if everything is butched up.