New charging problem

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superdart

superdart

Shade Tree Tinker Gnome.....
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The Dart has mysteriously started charging at 14v at idle and will climb to 16v when I rev the motor up to even just 1500rpms.

I guessed it was a voltage regulator. I had two more spares, and they did the same thing. Just to make sure, I went out and bought yet another one, and it did the same thing.

This all started right after I installed my new stereo system, but during all of this testing my stereo has been off, along with the amplifier. With the regulator disconnected I am only pushing 11.6v constant. I had the alternator tested at the parts store and it passed.

I am using the new style electronic Mopar black regulator, and the alternator is a 100amp rebuilt. I altered the charging system a few years ago so the sense wire for the regulator read direct battery voltage (same point at which the charging wire (4 awg) returned to battery from alternator.

I really am not sure what to do at this point. I think my alternotr capacity will not be enough for the car, and that going to to a Powermaster 140amp would be a good idea, plus they are internally regulated.

Currently my power draw includes:

20 amps for electric fans (when on)
60 amp potential for radio amplifier (never really turned it up)
7 amps for electric fuel pump
..plus everything else on the car.

Any ideas?

Also, who has run the 140 Powermaster, and what kind of modifications are they talking about when they say "slight bracket modifications" necessary?
 
I dont normally respond to electrical questions when there's a bunch of aftermarket addons but here's my best guess...
Either let it run long enough to charge the battery or buy a battery.
When you disconnected the regulater you in effect disconnected the altenater. 11. whatever is low battery voltage.
 
I would undo the amp and then check it. Also if you have another
battery. Switch it out and try it. If the battery has a cell
going out or shorted. It could pull to much volts.
 
I had this happen when converting to an electronic volage regulator from a mechanical one. It turned out to be the voltage wire feeding the regulator had a voltage drop from where I could not determine. I tapped into another hot wire in the engine bay that was reading battery voltage, and resolved the problem. That was 5 years ago and it has been fine ever since.
Brock
 
bvt: Actually I did the same thing a few years ago when I upgraded to my FBO ignition.

The testing I did was with the radio/amp off, no power draw aside from that for the memory.

A few people that I have talked to today have indicated the battery as a possibility. It is a Red Top Optima, but it is probably 5 years old, and it has been killed off (ABSOLUTELY dead) a few times. Maybe it's just on it's last legs after being abused so badly.

I cranked it up a few minutes ago. It was reading 12.29v at rest, but dropped down to 9.6v while cranking (started with minimal cranking)...then it charged at 14.64v at 1500rpms.

Just for testing, I think I will let it slow charge all day/night and see how it works in the morning....if the voltage appears normal, then I guess the battery was low/is dying.
 
Yes, it would appear to be a faulty battery. I took the Optima back where I bought it to test. It failed almost right away. It has ok initial voltage, but tanks quickly under load.

I don't have a new battery for it since they were out of Red Tops. I am going by their other location tomorrow to swap it out under pro-rated warranty.
 
Damn...battery didn't fix the problem. NOW what?

I had thought about using a 1 wire Powermaster 140amp unit, but they charge at 14-14.5v...If that is the case, what is wrong with using a 13.6 constant Mopar regulator?
 
Are you using one of the big capacitors on your stereo system power feed? If so try disconnecting it and see what happens. A capacitor stores voltage and it's possible it's storing excess voltage causing the high reading.

BTW: If you use the internally regulated alternator the battery voltage will probably drop because of the voltage drop from the alt. to the battery. It'll defeat your mod you did where you ran a sense wire right to the battery.
 
I'm not running any capacitors on the stereo, it's not that big of a system.

The troubleshooting has been done both with the stereo on, and with it completely unplugged. No change between the two states.

I am using all 1/0 cable for the battery cables and 4awg cable for the charging wire. There is very little voltage drop from the alternator to the battery.

Currently I feel there is something else amiss in the vehicle and throwing a new alternator at it won't solve anything.
 
superdart said:
I'm not running any capacitors on the stereo, it's not that big of a system.

The troubleshooting has been done both with the stereo on, and with it completely unplugged. No change between the two states.

Ok, that rules that out.
Click to expand...

I am using all 1/0 cable for the battery cables and 4awg cable for the charging wire. There is very little voltage drop from the alternator to the battery.

Currently I feel there is something else amiss in the vehicle and throwing a new alternator at it won't solve anything.
Click to expand...

I think your right that a new alternator won't solve the problem. Wish I had more to offer though but it sounds like you've been around the block on it. The only thing you might try is to remove the remote sense wire and wire it up like it was from the factory. I'm sure that should lower the voltage some.
 
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