Need suggestions - my amp gauge is acting like a tach

Or your battery is low on charge.

The VR still seems to be grounded OK, and I just bought it about 5 years ago, so I fooled around with the wires where they go into the bulkhead connector.

Thought I had it at first, because I started it up and the needle stayed between +10 and +20.

Then I poked around some more and closed the hood, started it up again, and the needle was pegging again.

Guess I'll go out and buy another VR and see what happens.....

Oh - also, I'll hook my battery charger and test the voltage/percentage level just in case that could be it, but I think the battery is good.

possible field wire grounded

Why not just by pass it all together using the MAD Electric upgrade. I will never again rely on the original for electrical status. It is the weak link for sure. Just do it and then add a Voltage meter and all will be good....

The new VR (NAPA - Echlin brand - $29) came with a sheet that had this test:

Disconnect VR, connect jumper wire to FIELD side of harness that goes to the VR. Start car, watch amp gauge while grounding the jumper wire momentarily. Needle should jump to the right, if it does not, problem is somewhere in the wiring.

Needle moved to the right, so that was good.

Also, I checked and re-checked all the wiring, and could not see any problems anywhere.

Installed new VR, started car, revved engine, needle pegged to the right, then settled down to around +10 to +15 and stayed there, so I don't know, maybe it's OK now. But the needle used to just stay steady slightly to the right of zero.

One other possible clue I should have mentioned, when I start the car the temp gauge spikes to the right for a second, then goes back to normal. Has been doing that off and on for years, but does it more here lately.

I'll play with it some more this weekend and remove the instrument cluster to check the back, but still would like to hear any more ideas.


I also like the idea of the MAD conversion.
I looked into that a couple of years ago but didn't get around to buying the stuff and doing the install.
I'm exploring Mark's site (madelectrical.com) but cannot find exactly what I remember from when I read up on it before. Do you have a link?

I thought there was something in moparts Tech Archives about the MAD conversion but could not find it there either.

Thanks to everyone for all of the ideas so far.

I'd slow charge the batt overnight & see if the needle is slightly to the right like it was way back. If not I'd take off both field wires from the alt and the connector from the reg & with jumper wires with alligator clips on both ends jump 12V from the batt positive post to one of the alt male field terminals and to the reg "top blue wire" male terminal and jump from the other reg "side" male terminal to the other alt male field terminal & jump from the reg case to the batt neg post & see if you're good at a fast idle. If so that tells you the hard components (alt/reg/batt) are good & the problem is in the wiring/grounds. The Madd upgrade has it's good points but if the overcharging ain't dealt with 1st the overcharging will fry something in the system & you'll see 15-16 volts on a voltmeter as opposed to the ammeter pegging. What Nanket said, clean the connections especially the bulkhead & reg ground after you've verified the batt is topped off & see where you're at

Thanks RapidRobert and everyone else - I haven't had time to do everything suggested, but the problem seems to have gone away.

The battery is still real strong (only about 2 years old). I checked carefully for shorts and cleaned all of the connections when it first happened - battery, VR, bulkhead, etc., but I didn't think that solved the problem at first.

Since then though, with short test drives it has not acted up. So I took I just took a nice 60-mile cruise, and everything was great.

I'll be keeping an eye on it, and will keep you posted if it happens again.