Ammeter at +20 on highway and even at idle

[Sendero]

The ammeter is near +20 if with idle and lights on and is near +20 when running on the highway.

With engine off, battery is charged to 12.75v. Terminals at the regulator plug read 12.75 when disconnected fron the regulator with engine off.

When the plug is connected back onto the regulator and engine running, the voltage at the ballest reads only 9.5 volts. Backtrack to plug on regulator and it reads 9.5-9.8 volts. I changed regulator with no change in symptoms.

Battery to frame ground is good. Regulator ground is good.

Are these the symptoms of a loose ammeter connection or a bad alternator?

[b5blue]

Take apart bulkhead connector and clean all the contacts first. Check out Nacho's threads on wiring they are super.

[Sendero]

Took the bulkhead connectors off and used an electrical cleaner on them and then a light coating of dielectric grease. reconnected.

Started the car and the same conditions occur:

1. Alternator reads 15.1 volts at idle.
2. Battery being charged at 14.8 volts
3. Alternator feed to ballast resistor terminal plug reads 14.1
4. Ballast resistor terminal plug feeding the coil & other( Brown and Drk Blue) reading 9.5 volts.

My assumption now is that the alternator to battery line ( with ammeter) is only dropping .2 to .3 volts so the ammeter connection should be fine.

I did not expect that the ballast resistor would drop approx. 5 volts at .002 ohms. That equates to a current of 2500 AMps! Impossible ! So that leads me to  the wire /terminals connection to the ballast. The much higher resistence must be there causing the 5 volt drop.

My guess is that the 5 volt drop is leading the regulator to sense approx. 9v and so the alt charges the battery more and so my ammeter gage is showing that.

[b5blue]

Now your cooking, I thought of your problem 2 days ago when I changed out my dist. and had to crank my engine over drawing the battery down. When I got it started my needle hit exactly 20. (I trickle charged it up before going for a test ride) I did notice my system worked better with the new MoPar regulator than it ever did with the aftermarket one I replaced a month ago. If you want I'll run my car with the lights on and give you some readings.

[Nacho-RT74]

ballast feeds the coil on 7-8 volts when hot and 9-10 volts rate when cold. Could it be some diff depedning on preformance on ballast but more less, that's normal. That IT'S function in fact.

the ammeter reading.... do you have something hooked directly to battery ? some relay ?

[b5blue]

I keep thinking "Battery" maybe a connection or acid is getting weak? With my lights on mine reads +5 or so on the gauge.

[Sendero]

I checked the connection and the wire actually fell out of the terminal to the ballast!
I fixed that yet the condition remained. So what is the problem? Well, I had the battery disconnected and I thought I'd better check something. The ammeter is reading 20+ with no power and engine off. It is the gage itself that has its zero at +20 now . I think it is time for a dash cluster re-condition.

So it appears that the gauge is zero'd at +20 but that doesn't explain why the alt is charging at 15 and feeding the battery at idle at 14.8 volts.

[b5blue]

Still thinking "Battery".....

[resq302]

Some auto parts stores will check your alternator and battery for free.  Nice easy and cheap way of ruling them out.

[FLG]

With engine off and nothing draining the battery or battery disconnected the amp meter should be dead center.

[b5blue]

  unless the gauge is bent.

[Sendero]

Went to Advanced Auto parts. They ran the tests. My 625 cold cranking amp battery was at 500. Weak battery. B5Blue wins 

[Nacho-RT74]

OH OK, I'm clear now!!!

With engine off and nothing draining the battery or battery disconnected the amp meter should be dead center.

needle is out of its place. Easy to fix. just remove the gauge and fit the needle on the magnetic plate back. Easy to fix, nothing needs to be bent just match the surfaces ( both have triangular surfaces )

I know is hard to understand, but you'll understand when removing the ammeter and detailing its parts. Don't worry. No need for an expert tech resto job

Somebody around had the same not too much time ago, and got the same situation. Got it to fix.

on the other side you can get discharge even with 14 volts. Charge is made by amperes not voltage, even is true both are related. Batt ( AS YOU NOTICED ) can get relation on that reading, High voltage reading but still not enough charge THATS why I trust more on ammeters than voltimeters, although both together is the best.

One example more about why ammeter must be kept.

[b5blue]

  now that's an E-Z fix!