I put new after market gauges in my powerwagon and replaced the amp meter with a voltmeter. The +pos side of the gauge is attached to the original wires from the amp meter. Would this cause my volt meter to show unregulated voltage directly from the alternator? Because when I rev it up it nearly pegs the voltmeter. I changed the regulator on the firewall (with another used one that I think is OK) but nothing changes..

Do you have the two original ammeter wires hooked togeather?
How is the ammeter wired?
Hooking the voltmeter on that circuit will cause a drain on th battery as the voltmeter will be hot all the time.

The correct way to do the install is to hook both original ammeter wires togeather. Wire the voltmeter Black negative to chassis and red 12 volt to a keyed source.

I do have the two original ampmeter wires hooked together and the neg on a keyed ground source with all the other gauges.

there is no Keyed ground, only keyed power.

Find a keyed power line and hook that up to the + voltmeter wire, then hook the ground wire to the chassis.

Oops sorry I guess I did hook it up to a keyed +pos

So far as the "voltmeter pegging" there is no such thing as "unregulated output" from your alternator. All cars will measure a SLIGHTLY higher voltage at the alternator output post than they do at the battery, this is because there is resistance in the factory wiring. YOU WANT THIS AS LOW AS POSSIBLE. Higher readings can be caused by a number of things, mostly related to old wiring/ connectors and too-small wiring, and the ever present, ever troublesome, bulkhead/ firewall connector.

You must have a good regulator

You must have a good battery

You must have a VERY low resistance ground path all the way from the neg. batt. post to the frame/ body/ engine/ alternator/ regulator

you must have a VERY low resistance path from the battery pos/ feed/ wiring/ bulkhead/ ignition switch/ supply to the regulator.

Any of this wiring or connections will cause an overcharge condition.

So far as your voltmeter, all you've done wrong is hooked it up to cause a constant drain. If you park the vehicle long enough, it will eventually drain the battery.

Okay found the problem. The new regulator I bought said to check the green wire between the alternator and the regulator. Apparently if it is broken and grounding out somewhere it will cause the alternator to overcharge the system (false reading from regulator). While checking the wire I noticed the field terminal on the alternator was loose and sparking when I wiggled the green wire. Replaced the alternator and all is well now. Thanks for everyones input!