Ammeter operation
Thread Starter
Instructor
Joined: Apr 2014
Posts: 179
Likes: 1
From: NJ
Ammeter operation
It has been so long since I had a car with an ammeter that I cannot remember correct operation. When the car is off, the ammeter is at 12 o'clock. Is that right? When I turn it on, the ammeter stays at 12, but if I rev it up, the ammeter moves just a TINY amount to the right (charging side). If I turn on the lights, I see a TINY movement to the left, but really small. Is this correct too?
thanks,
Mark
thanks,
Mark
Pro
Joined: Oct 2013
Posts: 506
Likes: 23
From: Union City TN
St. Jude Donor '15
It has been so long since I had a car with an ammeter that I cannot remember correct operation. When the car is off, the ammeter is at 12 o'clock. Is that right? When I turn it on, the ammeter stays at 12, but if I rev it up, the ammeter moves just a TINY amount to the right (charging side). If I turn on the lights, I see a TINY movement to the left, but really small. Is this correct too?
thanks,
Mark
thanks,
Mark
Melting Slicks
Joined: May 2001
Posts: 2,749
Likes: 776
From: Dadeville AL
It's not an ammeter. It's a BATT gauge. It measures a small voltage difference between two circuits and give an indirect indication of whether current is flowing to or from the battery. When the battery is fully charged and there is little electrical demand, the needle will be about straight up or slightly +. If the alternator is good and the battery low or demand high, the needle will show a higher + reading. If the system is demanding more current than the alternator can provide, it will show a - reading.
Team Owner
Joined: Jul 2006
Posts: 22,182
Likes: 4,178
From: Kannapolis NC
Assuming you are asking about a 65, because you didn't say and you don't have anything in your profile about it, and your profile pic appears to be a 65, what kellsdad said is correct. It's a voltmeter, not an ammeter and it measures the small voltage drop along the low amount of resistance of a piece of wire that goes from the horn relay to the starter solenoid. The movement you see is normal for a battery that is charged.
You should fill out your profile. Or better yet, say what car your asking about in your question, they really aren't all the same in C1 and C2 combined forums.
You should fill out your profile. Or better yet, say what car your asking about in your question, they really aren't all the same in C1 and C2 combined forums.
Thread Starter
Instructor
Joined: Apr 2014
Posts: 179
Likes: 1
From: NJ
Yes, it is a 65. I updated my profile. Thanks for the all the info, I assume it is fine. I will make a small test later today just to be sure....
OK, I did the test: I left the lights on for 30 seconds, I could see the meter go negative. Then, when I turned the car on (lights off), the meter was positive for 10-20 seconds, then went slowly to 'zero' -- so it works like it should. And it does say "Volts" or "Voltage". Thanks all.
Mark
OK, I did the test: I left the lights on for 30 seconds, I could see the meter go negative. Then, when I turned the car on (lights off), the meter was positive for 10-20 seconds, then went slowly to 'zero' -- so it works like it should. And it does say "Volts" or "Voltage". Thanks all.
Mark
Last edited by msk914; Oct 12, 2014 at 11:32 AM.
