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Amp gauge goes down but not up?

jmbass98

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The amp gauge will drop when I turn on headlights, brake lights, and fluctuates with turn signals the way it always has. But it does not move past 12 o'clock and doesn't react at all to throttle. Even when it drops below 12 o'clock with lights and such on, it does not move up at all with increased RPM.

Usually I'd think this is a gauge issue of some kind. But it did not do that before at all. And now my windshield wipers work extremely strangely. Usually will not react when I use switch. Will sometimes turn on minutes late. When they do work, they stutter hard. So obviously some electrical issue just appeared out of nowhere.

I replaced timing chain and water pump. Possible that I bumped a wire somewhere in engine bay, but I cannot for the life of me figure out which one. Could voltage regulator have gone bad, as well? It's mechanical.

Thoughts?
 
Faulty alternator, forgot to replace wires, or wire connected incorrectly.
 
Engine and year would probably help diagnosis as well...
Doesn't really matter, he said he replace the timing chain and water pump. You have to remove the alternator for either small or big blocks. There is no charging now, so it can only be the alternator.
 
Check your wiring.

Stick a voltmeter on the battery and verify no charging while running.
 
Don't trust your gauges, use a quality volt meter to verify that your charging system is performing correctly. I agree with the other posters, sounds like a wiring issue after the recent repair.
 
Alternator not charging, or charge not going through alt wire up to main splice. There is no other posible issue.

Sure the alt could be not charging for several reasons:
Damaged or disconnected regulator.
Brushes damaged or disconnected.
Rotor damaged or some other internal alt issues.

And alt wire could be getting issues at bulkhead, not allowing to reach the main splice for the load.

Gauge is fine. If was damaged wouldn't read anything. The main splice is going thought the ammeter from batt to alt direction. So is reading correctly, the load to source everything on car is coming from batt, so is getting discharged and ammeter is showing you that.

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Wipers issue could be another deal, not really related to this. Sure with glass dry and working just with batt it will also work slower than should be. Wiper motor sucks lot of load, similar to the blower ( AC-Heater )
 
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On the best charge status and really nice alt, with a fully charged batt you should get this ( bulkhead disposition based on 71/74s )

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But if batt is slightly discharged and alt is able to source the batt load request along with the car demands, this should be the reading ( and the loads flow )


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If the alt is not able to source all the car request, the batt will supply what is missing and this is the reading and load flow ( tipical on Mopars with poor stock loads capacity at low RPMs )

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Then when you give throttle after the previous status, you get this:

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Now you know what the ammeter readings mean


AMMOUNT OF LOAD IS REPRESENTED BY THE ARROWS THICKNESS
 
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And and extra advice. Make the mantenience to wiring and upgrade the alt for an alt able to give no less than 40-45 amps iddling. The best stock alts from 60s and 70s weren't able to source more than 25-30 iddling, and some maybe even less. This will stress out the wiring and ammeter getting high loads when batt is discharged and giving throttle. Keep the batt out of the game the most as posible with a good and powerful alt and the charging system will be relaxed.
 
Thanks for the info! Ended up being a bad voltage regulator. Upgraded to a solid state one and now it charges properly. The wiper issue persists though, which is very annoying... idk what I could have messed up while replacing a timing chain and water pump that would have affected the wipers, lol. But I'll make a separate thread for that.
 
So just a heads up... The new voltage regulator only seemed to solve the issue for about 3 days. Now a new regulator does not fix the issue at all. Been through two more. I replaced the alternator entirely with a brand new one. Nothing.

Oooof... lol. Going to start replacing the wiring harness here soon, hopefully that does something.
 
I had a very similar issue. Ammeter was not reading properly, my tach was all over the place, it read 3,000 rpm at slightly above idle. It turned out to be loose connections at the ammeter. I’m willing to bet that is your problem
 
I ended up connecting the two wires that connect to the ammeter together thus by passing the meter altogether. Everything works fine now.
I will address the ammeter at a later date
 
Check the Packard charging connections at the bulkhead disconnect. Especially the ALT BATT black wire. Check the condition of that same wire running from the bulkhead disconnect to the number 1 weld splice. That wire and connection was bad in my car causing mostly the same symptoms you are having.

Previous owner kept changing out the alternator and voltage regulator neither of which were the problem.. Also check the condition of the studs on the ammeter gauge itself, make sure the studs are solid and not loose and the wires connected to them are solid and not loose.

For details look up the “Chargeless Charger” thread..
 
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