Wacky ammeter behaviour

Mike Simard · #1 (**permalink**) 03-22-2006, 01:53 PM

I just replace my Ford type alternator because one of the terminals was coming loose internally. Now that I have the new one on, the ammeter will bobble between a high charge state and zero causing the idiot light to flicker as well. I just replaced the external regulator and it's still happening.
I have an Optima yellow top and have been doing a bit of jumpstarting during a recent engine install. I've been using a 2a battery charger and it seems to be charged. Anyone know whats going on?

Goober · #2 (**permalink**) 03-22-2006, 02:16 PM

Smiths or Lucas amp gauge may be the culprit. Get a cheap one from your auto parts store and see what it does.
Mark

strictlypersonl · #3 (**permalink**) 03-22-2006, 05:20 PM

While I'd check the ammeter first, I doubt whether that's the culprit. Check the grounds (alternator and regulator).
It's not unusual to get a bad rebuilt alternator, though.

Mike Simard · #4 (**permalink**) 03-23-2006, 09:53 AM

Hmm...I tried disconnecting my battery while running, I kept jumper cable hooked up to the battery cables going with the other end on the battery in my truck, thus simulating swapping batteries. The ammeter shows normal behaviour then. This implies an internal short in my battery. WTF? This battery has had an easy life, it has needed recharging after running it down recently but c'mon.

Tony Ripepi · #5 (**permalink**) 03-23-2006, 10:32 AM

HI Mike,

I've had the same kind of experience with the Ammeter in my car when I had the Optimas installed....they seem to be very suseptible to shorting internally when you run them down to dead and then try to recharge.

I had to replace the two six volt red tops and the problem went away. My issue had to do with the alternator not getting the initial exciter voltgae through the light circuit. I used the Optimass again because of form factor, they are installed behind the seats in my Shelby.

Also went the route of replacing the regulator etc.

I do not like the Optimas and others have had the same experience.

Tony R.

Mike Simard · #6 (**permalink**) 03-23-2006, 10:59 AM

Well, I just tried a new Optima and still acts the same, I really don't know what to make of this. Goober, maybe I should have followed your advice first, the only thing left is the ammeter and wiring. If it's the ammeter than it must be a short because the idiot light flickers after the ammeter bounce off of it's high reading, the idiot light senses a lack of charging at the regulator. But what the heck do I know.
Edit: tried taking the ammeter out of the circuit but the idiot light still flickers.