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ddub
07-10-2017, 01:46 AM
I noticed today that when I lower the power window in my 63 Avanti the ammeter shows charge. How can that be? Operating any other electrical accessory shows discharge as expected.

tsenecal
07-10-2017, 11:27 AM
The weight of the window dropping is turning the motor into a generator and it's making power! Just kidding. Sorry , but I do not have any idea what would cause that. Do any of the other accessories create the same result?

tsenecal
07-10-2017, 11:33 AM
I just read your post again and noticed that nothing else causes the problem. Can't think of anything else to try. You could read the amp draw between the switch and the motor with a multi meter, but it obviously has to be drawing power.

Dwain G.
07-10-2017, 12:41 PM
Power window motors spin in opposite direction by reversing polarity to raise and lower. This makes the ammeter temporarily read backwards. If you are getting a lot of needle deflection it could indicate a problem with the motor.

RadioRoy
07-10-2017, 01:28 PM
Power window motors spin in opposite direction by reversing polarity to raise and lower. This makes the ammeter temporarily read backwards. If you are getting a lot of needle deflection it could indicate a problem with the motor.

I'm having a lot of trouble with that explanation. Any drain on the system will make the ammeter read discharge.

rstrasser
07-10-2017, 03:03 PM
ddub;
No your power windows are not charging your battery or any other magic. When Studebaker installed the relay and circuit breaker for the power windows they powered it from the wire that goes from the ammeter to the battery. The ammeter shows the amount of current going to the battery from the alternator. It has no way of knowing that some of the power was being diverted to the windows.
All the other current using items in the car are connected on the alternator side of the ammeter.
I realize this explanation is a clear as mud.
The ammeter is intended to show the amount of current going into the battery. When the battery is fully charged and the car is running the ammeter should read 0. In other words the current being used to run the car is equal to the current being supplied by the alternator. When the alternator does not supply enough current to meat the load the meter reads negative.
Ron

ddub
07-10-2017, 03:13 PM
That makes sense, I think. So do others see this same behavior?

Bud
07-10-2017, 05:16 PM
My Avanti shows a fairly high rate of charge when the power windows are operated. I don't think you have a problem if the windows are operating correctly. There is no magic to the power window wiring and the deflection on the ammeter will depend on which side of the ammeter has the power wire to the window relay attached to it. As long as the ammeter returns to normal after the window switch is released, you are good to go. Bud