alternator is over charging and the amp gauge is bouncing? Help?

[brads70]

I have a brand new alternator and a new MSD Ignition. Car runs and starts great but the amp gauge keeps bouncing from half way to full charge? almost 16 volts( 15.89) at the alernator lug? Any idea's? Something is not right, and electrical is not my strong point! LOL

[djwhog]

Is the MSD grounded good and did you install a decent body to engine and or body to battey ground too?  sometimes it is just a poor ground.

[72cudamaan]

slipping belt maybe

[elevenssc]

I find it very curious that you are having an over voltage situation with your MSD and I'm having an under voltage (12.5V) situation with my MSD (externally regulated alternator)

Are you using an externally regulated alternator?  If so, how did you wire in the voltage regualtor?  From what I'm learning about the Mopar charging system, the bouncing voltage sounds like it could be a regulator issue (if you are using one).

Electrical is not my strong suit either.  It's a pain getting the smoke back in the wires...

[BIGSHCLUNK]

Although I'm still in dipstick hell, I took NIKKI out tonite to see how the new steering feels. My gauge was pegged just about the whole time, was fine last year, and NO new electrical additions....    I thought now what ?!!! 

[Chryco Psycho]

sounds like the reg is bad , if the seal is open behind & mosture gets in I have had the same issue with the alt intermittently charging at max output

[brads70]

Yep MSD is grounded good ( right at the battery ) and I did install a new engine to body ground as well as battery to body ground. I guess I'll try a new voltage regulator?   I was really hoping to be driving it this weekend!
Thanks for the replies!

[MEK-Dangerfield]

Brad,

  It could be the voltage regulator, or the fact that it isn't making good contact to the body of the car. I cheated and sanded a little around the screw holes, but it need to be tight against the body of the car. The other question is the battery. If it is real low, that would cause the regulator to go into overdrive. Mine typically goes to the high side at start-up, then settles just to the right of center after a few moments of getting it's bearings. 

[brads70]

I installed a new VR today. And the amp gauge is now steady! What sort of voltage meter readings should I be seeing at the battery? and at the alternator threaded lug?
 I'm getting 14.4 at the battery and 15.08 at the alternator lug all at 900 rpm. I reved up the engine and the battery voltage didn't change, still 14.4.

[mopar12372]

if i where you the amp gauge would be bypassed before the thing melts your wireing . get a external volt gauge.
common problem with old mopars. get the denso alt from mancini to eliminate charging problems that the mopars have too with out a worry.
imop--->bill

[brads70]

I installed a new VR today. And the amp gauge is now steady! What sort of voltage meter readings should I be seeing at the battery? and at the alternator threaded lug?
 I'm getting 14.4 at the battery and 15.08 at the alternator lug all at 900 rpm. I reved up the engine and the battery voltage didn't change, still 14.4.

BUMP
anyone know what voltage readings are correct?     If everything is good as it should be what does the Amp gauge do? Mine is about half way over in the + side?  and not always steady is this normal? The battery was out of another car, it seems ok always starts the car with no problems , even with the stereo on for a couple of hours before?
Also... I have a heavy dark blue wire and a smaller dark blue wire, looking at the wiring diagrams of the CD disc I have they are both going to the VR but what were do they connect to in the engine bay? The small dark blue wire I have going to the alt. and a smaller dark green going to the other spade connector on the alt. were does the heavy dark blue go to? At the moment I have it running to the relay to turn on my electric fan? ( very small wire so I know it doesn't draw much voltage)

[Chryco Psycho]

not running battery voltage should be 13.2 running you should be 13.6-14.2
the dark blue wire is the 12 v feed from the ign , it should go to the ballast resister , VR & the field on the alt , the gren wire from the other field connection should run back to the VR , the VR switches the ground on the field to make the alt charge , still sounds like you have a problem Brad

[Bullitt-]

   If everything is good as it should be what does the Amp gauge do? Mine is about half way over in the + side?  and not always steady is this normal? The battery was out of another car, it seems ok always starts the car with no problems , even with the stereo on for a couple of hours before?

   Sounds about right to me IF your battery needs charging.... When I started working on mine 4+years ago I put a cheap battery in & relied on the car & every now & then a battery charger, as time went by the battery always needed charging & the AMP needle was always on the + side.  Last year I got a good new battery as well as a Battery Tender Jr. that keeps the battery charged all the time. Now the AMP gauge indicates a small charge for a while then settles back to the middle.....All that being said I'd suggest you test the battery for full charge.

[brads70]

I'll try that Wade, Thanks!   I to have one of those battery tenders, just haven't hooked it up yet. I was gonna use it for winter storage.

[brads70]

   I think I have solved my issue. I ran a wire from the alternator lug to the battery and now the Amp gauge is right in the middle! I have the electric fan and the MSD running right off the battery.