Charging problem (again)

[Basoline]

Due to a loose connector on the +pole of the alternator, my battery is dead and voltage regulator too. The connector welded itself through the thread! O_o

I replaced the battery, voltage regulator and alternator.
- battery is in the trunk
- alternator is singlefield from a 68 /6
- voltage regulator is mechanical

Charging voltage on idle is 12.6 volts
Charging voltage revving is 15 volts

Trouble started after installing an aftermarket electric fan...Fan is grounded to radiator support and connected to starter-relais via a switch.

AM/Meter needle is pointing to the right but when driving faster she jumps up and down. But when on the freeway, everything looks stable.

Any guesses what could be wrong?

Thanks for the replies.

 

[morbidgoat]

alt belt too loose i just had a problem similar to that going to a chrome plated one wire alt. being chrome plated the belt had to be a lot tighter, but any way it was only charging like 12.5 at idle and would jump when reved. tightened the belt as tight as i could get it and now gives me around 14.5 at idle. this might not be your problem but sometimes its the little things that are over looked

 

[Basoline]

No, belt is tight enhough.

Could it be that a) the battery is too weak or b) the alternator is too weak? Not enough amps?

 

[Basoline]

I was going to replace the current setup by a 100amp one-wire alternator:

http://www.summitracing.com/parts/MCH-P595/

What do you guys think about that?

 

[HitIt]

I think the stock output alternator should be good unless you have a lot of extra electrical accessories. Just a fan added on should be ok.

After the wire got welded on, did it cause any other wire damage in that wire in another location? I'd test that wire first for shorts first. Removing it from the alternator and regulator, and running a tempory jumper wire is the quickest way to see if that wire has a problem.

Did you ground the alternator case to the engine when you put it back in? Those single wire style alternators need one pole grounded.

If you disconnect the electrical fan, does it still have the same problems?

Are you seeing this just with the stock amp gauge? Try doing your test with your electrical tester carefully hooked up to see if you're getting the same results.

Also of course double check the work you did replacing the parts. Could have something funny there.

Anyway, that's what I would start with.

 

[Basoline]

Alien applications:
- gauges (tach, oilpressure, watertemp) that need light.
- electrical fan

There was no wire-damage.
New (temporary) alternator is from a /6 car. Everything is grounded perfectly.

I don't know if the electric fan is the cause of all trouble. The situation I described above is AFTER I disconnected the electric fan.

We measured the volts during a short drive underneath the dash with an electrical voltmeter. AMmeter is jumping, voltmeter isn't.

The AMmeter is first nice stable to the right during acceleration. Then it's starts jumping. When riding in the freeway, the needle is stable again.

 

[The 500 Foundation]

could be just the old guage.
I had one that did it for years with no ill effects

 

[HitIt]

I thought it might be the old gauge too... that's why i'd try hooking your meter up and measure the amps to see if it's really jumping around.

But it sounds like the gauge was fine before, so either the gauge got fried (which is soooo easy) or there's a real problem.

So the alternator was an old one? Maybe take that into the shop for a test, or throw another one on and see if the problem persists.