Argh. Ok, I have a 74 Dart. A few weeks ago I was having problems starting my car, my battery wasn't holding a charge. My alternator WAS bad, so I replaced that. The problem was still there, and I noticed the voltage was fluxuating a bit (almost 1 volt down) so I got a new one. Then my battery was way under 12 V so tried to charge it up, wouldn't hold a charge so I bought a new battery as well. Ok. Everything was GREAT...for a week. Then today, it was doing the opposite. It seemed that it was overcharging so I bust out my multimeter, open the hood and notice right off that water is slowly bubbling out of the cells of my new battery. I measured the voltage. Off it's 12.3 V, on in neutral it measured about 15.5, and when I accelerate it goes up to about 17 to 17.5 V. That seems a little high, but I am not educated on these things. What do I need to check to fix this problem?

I appreciate any help,
thank you.

Make sure that new voltage regulator is grounded very well.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Well I tested the ground, it's grounded to earth. Or at least I assume it's ground, there are only 2 wires coming out of the voltage reg. one blue, and one red. I can't tell exactly where the blue wire goes, and the red of course goes to the alternator. Is there a way to test the voltage regulator? Sorry if these are stupid questions, I'm new!

The metal case of the regulator is the ground. The blue is voltage sensing. You should have 0 ohms between the case and the Neg. Bat. terminal. If not check for a clean regulator mounting surface and check the body ground strap.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Time for a new electronic voltage regulator....

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Okay, I did the test. The casing is grounded. What next?

PS-I believe I do have a electronic voltage regulator, it's sealed...I've never seen the mechanical kind, but I heard you could get into those kind.

In your first post it hard to see if you just replaced the altenator or you went back and replaced the regulator too. If not it seems like its time to replace the regulator also.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Check the IGN feed to the regulator for full voltage, the ground there, and for a short on the low FLD side of the alt. A damaged brush assembly or shorted wire could be turning your alt on full tilt.

If you unplug the regulator and the voltage still goes high, you've got a short on the FLD side somewhere; if not, the problem is with the regulator or its connections.

Hey, don't know if you'll see this or not. Just wanted to say thanks for all the help! I got it all going again, no more electrical problems

It ended up being a short off the low fld of the alternator, just like you said...it was my fault, I put the nylon washer on the other side of the screw not paying attention, I was scratching my head for hours... Don't know if I should admit that, but hey...I'm new to this. It's all good now!!!

Thanks again to KBB_of_TMC and everyone else!


Cheers.