Ive gone through 2 voltage regulators this week. What would be causing these to go?

Bad battery, bad alternator, poor conections at the battery or regulator. It is a good idea to replace the alternator and the regulator at the same time. Also you should verify the battery is in good condition. The solid state regulators are ok but I have seen people remove them in favor of one that is 30-40 years old and work way better than a brand new Japanese one.

Dave

I "chased" a charging problem on my El Camino for the past 2 years and finally found it after replacing the alternator twice, the battery once and the voltage regulator twice. The problem was the car would charge fine, but every now and again it would over charge like nuts or not charge at all.

The problem was none of the above, I had the wiring running from the starter to the alternator grounding itself, from time to time, on the wire holder at the starter. Fixed the wire's insulation with a little black tape and she is good to go.

I suppose what I'm getting at here is to make sure that you don't have another problem like I did before you install another voltage regulator.

I put a new $65.00 regulator on my 68SS and had overcharging at high RPM's (no adjustment) so I went and bought a solid state regulator from Autozone for $15.00 and it works fine at all RPM's.

Sometimes you don't get what you pay for! ;)

Ive gone through 2 voltage regulators this week. What would be causing these to go?
Why do you say they're bad, under-charge, over-charge?

As was stating above pbly a grounding issue ......make sure you have a ground strap from Regulator body to body

just installed the brand new one. Made sure all connections and grounds were good. I did notice that the postive battery cable was very loose at the battery so i tightened it. Would that have been causing it? Its reading like 13.1 volts when started and 12 when key is on. When i rev it, it doesnt seem to jump up any like the last one did. Also, when the ac is on...it jumps down to 12 when driving and even lower at a light. Is tat normal?

On a 66, the high current (63A) alternator requires a specific voltage regulator with a field coil on the underside of the regulator. Since you have AC, you most likely have the high current alt. The lower current alternator for non AC cars uses a regulator that does not have this coil on the underside. It may be that the alternator and regulator are not matched. Check the NAPA site for pics. My .02

I recall it had a little coil type thing o the underside. The ac hasnt worked in 30 yrs on it so i have no idea if the stock alternator on it is right. Is there a alternator for ac cars. No one has asked me at these pasrts stores if the car has ac

Its reading like 13.1 volts when started and 12 when key is on. When i rev it, it doesnt seem to jump up any like the last one did. Also, when the ac is on...it jumps down to 12 when driving and even lower at a light. Is tat normal?
First Guess: Not a thing wrong with the regulator. Your alternator is wiped--won't throw rated voltage/amperage.

'Course, that is just a guess. It is SO easy to test the alternator/starter/battery on-the-vehicle which is where it matters--but it takes money to buy the equipment.

My recommendation: Go to Sears or any other chain "auto center"--or go to any independent auto repair shop--and pay for a "starting/charging team" test.

You want to know (in writing):

Battery temperature (only really important if you're in a cold climate--but it takes two seconds with an infrared gun...)
Battery Open Circuit Voltage (OCV)
Battery load test result
Charging system regulated voltage
Alternator diode condition (ripple voltage)
Alternator max amperage (full fielded)
Alternator max amperage (through the regulator)
Starter amperage draw during cranking
Parasitic drain on battery when everything is shut off.
Voltage drop from + post of battery to + post of starter during cranking (1/2 volt MAX)
Voltage drop from + post of alternator to + post of battery when alternator is full-fielded (1/4 volt MAX)
Voltage drop from engine ground to - post of battery during cranking (1/2 volt MAX)
Voltage drop from alternator ground to - post of battery when alternator is full fielded (1/4 volt MAX)

Half-an-hour's labor rate should cover it nicely--but they'll bitch about having to do the voltage drop tests. (not hard, all the components should be easy to get to except the + connection on the starter. That's why they're the Pros--right?)