Voltage Regulators failing?

[dubseven]

Just had a voltage regulator die in my 68 D200. Put a new one in, died within 20 miles. Bad part, or should I be checking something else?

[cudamike66]

Check the following : voltage regulator mounting needs be clean and tight. Rust, accumulated dirt/road grime, painted surfaces or loose connections can produce a no charge reading. Check the wiring harness bulkhead connection for corroded/loose/burnt connections. Lastly, check the connections at the ammeter itself for loose/burnt/corroded connections. Disconnect the battery before doing this

[dubseven]

Put a new regulator in, died almost immediately. Will recheck grounds. Possible alternator is bad and or killing regulators?

[dubseven]

Regulator case on firewall to engine block had less than half an ohm resistance. Voltage is getting to positive side of regulator, but no ground on the field output. Had alternator checked, its fine. Did I just get a bad regulator? FIrst one was a 3 wire, which I guess was incorrect. Second one died in a mile, but it was a digital style 2 wire.

[dubseven]

Got a second VR706 from AutoZone, drove and idled fine, charged fine. Second or third WOT pull killed it. Any chance my high output PowerMaster alternator is too much for it to handle? If so, which regulator do I use?

[Hobcobble]

Got a second VR706 from AutoZone, drove and idled fine, charged fine. Second or third WOT pull killed it. Any chance my high output PowerMaster alternator is too much for it to handle? If so, which regulator do I use?

What is the rating of the alternator?
John

[Oldguy]

Probably the alternator. There should be a regulator available from Powermaster. Good luck. Mike

[Hobcobble]

Someone near a FSM should be able to post up the output of the stock alternator
[68amps? ]. I'm not sure if by running something much more stout will
pop your regulators or not..... but I have heard that you run a greater risk of
a wiring harness BBQ....
John

[dubseven]

100a. Just tried an old constant voltage regulator and added a massive ground strap from the firewall where the regulator is mounted to an intake manifold bolt. That lasted maybe 10 minutes..... Powermaster said a factory regulator should work fine. I had the alternator tested as well and they said it was fine. Possible they missed something?

[dubseven]

Also of note.... My battery is mounted under the bed and grounded to the frame rail. Cranks and runs extremely well otherwise.

[dodgeboykim]

Also of note.... My battery is mounted under the bed and grounded to the frame rail. Cranks and runs extremely well otherwise.

Do you have a grounding cable of sufficient size from the frame to motor.

[dubseven]

Solid metal motor mounts

[Hobcobble]

Solid metal motor mounts

What did you do with the rubber mount insulators then?
John

[dubseven]

What do you mean?

[kurt]

Steel Mount

[Hobcobble]

What do you mean?

I was wondering what you did to make you motor mounts solid metal.
If you used something like what Kurt posted, my question is answered.
John

[dubseven]

That is the exact mount I used.

[kurt]

Did the powermaster alternator work for a long time before the regulators started dying or is this a recent change?

The regulator only controls the field current through the wire wrap on the stator (spinning part). Did you check the current output of the alt when you rev the engine? If the battery or some other load asking for a lot of current possibly the regulator is not able to feed the powermaster stator and fries. Just get a cheapo amp gauge and put it in series with the alt output wire to check it.

Kurt

[dubseven]

It worked fine for 5 months or so.

[Hobcobble]

Do you by chance have an original equipment alternator to throw on?
John