Hi all-- On the way back from driving in a Mardi Gras parade today (very crazy) my GT started acting goofy. Here is the timeline for your consideration.

Replaced Voltage Regulator as one of my 12 v circuits was putting out 14.3 volts at the fuse box. Ammeter was wiggling widly at idle. The new Volt. Regulator seemed to calm down the wigglin' needles. However, now the ammeter shows to the left of center--on the discharge side.

Fired up the car this AM and no horn. It is there, but very very very soft. Hitting the button causes the ammeter to swing way over to discharge.

Ran the parade without trouble. The ammeter needle moved to discharge when we were sitting still, but as soon as we started rolling, it went back to just left of center.

On the way home today, my car suddenly started stumbling between 30-45---hesistating, loading up and such. I can work my way through the stumbling and it runs strong over 45.

The turnsignals are very dim, now, and slow, too. Turning on the AC makes the ammeter swing waaaaaay over to discharge.

Ok, since my wife is sick and I'm home with my little boy, I haven't put a voltmeter on it to see what is going on.

Ideas? Does it sound like my alternator is going south? Bad Volt. Regulator? What? I'm at a loss.

-Paul :bang:

 

First choice would be the alternator, with battery as second choice. I'd pull both and take them to the local parts store for a free test...

 

Good choice above, also don't forget the simple belt tension, or a loose ground wire. Either one of those could cause the same problem. Good Luck.

 

Good choice above, also don't forget the simple belt tension, or a loose ground wire. Either one of those could cause the same problem. Good Luck.
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Joe--Ground wire as in the ground off of the battery? Belts seem ok, maybe a tad loose, but nothing too bad.

Tried to start the car to check voltage, but the battery is deader than Cesear. Got a charger on it now. Hope to have some readings tonight.

Sigh.

--P

 

sounds like a bad connection somewhere or the battery but I don't really know what I am talking about.

 

My guess is the alt.

 

I'm auto mechanically challenged but I have a funny suggestion as to your problem.
DO NOT LOOK DOWN IF YOU DO NOT HAVE A SENSE OF HUMOR





Did your car have too much to drink today?

 

Sounds like a cell in the battery went south. If the charger reads a full 12 amps and then drops s-l-o-w-l-y to 2 amps or less in about ten minutes, it's usually a sign of a toasted cell.

 

It was a mardi gras parade, you know. I did gas her up with Premium. . . . Hmmmm . . .

Funny!

You have to have a sense of humor with a 39 year old car--otherwise, you'd toss yourself under a UPS truck!

 

Sounds like a cell in the battery went south. If the charger reads a full 12 amps and then drops s-l-o-w-l-y to 2 amps or less in about ten minutes, it's usually a sign of a toasted cell.
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The charger read 12 amps, and then went down to about 6 in less than 5 minutes. I haven't checked it since.

If I drag in the alternator to the parts house for testing, it is going too.

Hmmmmm. . . . That is one that I hadn't thought about.

--P

 

3 hours has it to 75% charged. I'll check after Adam goes to bed in 1.5 hours.

 

almost 100% now. The voltage goes down at the battery the more stuff I turn on. Headlights on and car running, I get 12.5 volts. With everything on that I can think of, I get 12.0 at the battery.

Alternator?

 

If you have an ammeter with a wide enough range for your alternator, you can disconnect the "bat" terminal from the altenator and connect the ammeter between the terminal and wire. Start the engine, turn on lights and other electrical components. If the reading is approximately the same as your alternators' output range, then its working fine.

Or, take it to a parts store and "spin test" it.


Perhaps it was just crud on the terminals?

 

Here's one for you. Swapped out the new Volt Reg for the old and my voltage at the battery jumped from 12.4 to 14.3 at the battery with the car running. I think I got a lemon regulator. I can't think why else a simple swap would get the voltage back up.

With the lights on, the voltage dropped to 13.34. Is that still within the range of ok?

Lesson here: Keep your old parts for awhile!

 

You're back where you started. I thought you replaced it because you were getting 14.3?

I'd still have the alternator tested when you return the V/regulator. What brand regulator?

 

You're back where you started. I thought you replaced it because you were getting 14.3?

I'd still have the alternator tested when you return the V/regulator. What brand regulator?
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I feel like I'm chasing my tail. I replaced it because I had thought I might have zapped the underhood harness with a bad short. My ammeter wiggles widly at idle, but smooths out at above idle.

At least now, wigglin' needle or not, I seem to be charging!

I'm not sure of the brand. It is going back bright and early tomorrow. Not a motorcraft.

--P

 

There's the lesson! It wasn't a Motorcraft..... B)

 

Are you certain you have the correct regulator? Verify the connections to the regulator. Verify it is grounded. Put the old regulator back on and see what happens. B)

 

They may have given you the wrong regulator it sounds like. The wiring is different from year to year on the spades and connections to them or not.

I was refering to the ground cable to the battery and where it bolts to your engine block.

It is common for corrosion on the battery posts to cause bad voltage, also any oil or road gunk built up on your engine/ground mount can certainly raise heck with it.
Sometimes you can turn the cable on the battery post and it will drop voltage or smooth out. I have seen battery posts too small for the connector used to secure it. But that doesn't sound like your problem.


With your engine running, you should be in the 13 volt range. When you rev the engine the voltage should surge a bit but then stabilize. If it keeps going up then the alt could be bad.

I hope this helps. Electrical gremlins are horrible. I am rewiring my car to hopefully eliminate this stuff in the future.

Good Luck.

 

I'm running the old regulator now. Battery has a full charge and the ammeter is showing just right of center a hair towards charge. Ground is clean. Battery posts are clean, It had to be a incorrect regulator. Went back to the parts house and have a Motorcraft one on order. Apparantly, their parts book show two models--one with a transitior, I believe and one without. They gave me the one with. My catalogs show differing models for cars with either power tops or AC and cars without.

We'll see if the motorcraft one settles the needles and gives me the right voltage. Comes in tomorrow. . .