1972 Ammeter Test
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Read our "lips": IF THE METER MOVES WHEN YOU APPLY A SMALL VOLTAGE TO IT, THE METER IS FINE!!!
Put key in ignition and turn to ACCESSORY position; watch ammeter as you turn on your headlights (they won't come up, of course; but they will light); the current to power the lights should cause the ammeter to go to the 'discharge' side around 5 amps. If you depress the "Brights" floor-pad button, that will move to around 10 amps.
If that test shows nothing on the ammeter, then there is a problem somewhere in the wiring circuit going to the meter or with the connections to the meter in the dash area.
Put key in ignition and turn to ACCESSORY position; watch ammeter as you turn on your headlights (they won't come up, of course; but they will light); the current to power the lights should cause the ammeter to go to the 'discharge' side around 5 amps. If you depress the "Brights" floor-pad button, that will move to around 10 amps.
If that test shows nothing on the ammeter, then there is a problem somewhere in the wiring circuit going to the meter or with the connections to the meter in the dash area.
Instructor
Joined: Nov 2014
Posts: 183
Likes: 0
From: Belmont NC
St. Jude Donor '15
The meter obviously works. Locate the two orange fusible links in the ammeter circuit(one attaches to the horn relay and the other is under the wiper motor where two #12 wires are spliced together). Then check for continuity from the meter connection to the end of the appropriate fusible link.
DUB: I don't mean to override the OP but noticed your in Charlotte. Are you in a Corvette club of any sort? If so, website?
Thread Starter
Racer
Joined: Feb 2013
Posts: 364
Likes: 39
From: Sebastian FL
'72 ammeter fixed
Ammeter needle doesn't move on my 1972 BB, a/c, pw, pb, ps 'Vette. Charging system seems to work OK. When I got the car about 1 1/2 years ago it moved a little for a short time. Now I am checking it out. With battery connected and two leads off ammeter I read 12.4v on both. With engine running I read 14v on each. When I check resistance with wires off ammeter but ammeter in console I read 0 to .4 ohms resistance. When I connect 1 1/2v battery across the terminals, ( ammeter still in console but disconnected), the needle immediately goes full scale. Any thoughts on what is going on and how I can determine what to fix?
Thanks
Thanks
Thanks to everyone for your assistance. I never would have found the problem without your help.
Phil
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
Finally my ammeter is working. It appears the fusible link at the horn relay was creating too much resistance. I ran a new line with a 2 amp fuse from there to the ammeter and it works.
Thanks to everyone for your assistance. I never would have found the problem without your help.
Phil
Thanks to everyone for your assistance. I never would have found the problem without your help.
Phil
Now go to your local parts store that has a HELP section and buy the correct fuseable link. Fix it right, i.e., correctly. 
Pete
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
Just use one of the wires that goes to the ammeter? That'd be a good way to introduce a parasitic draw that will help to drain the battery quicker.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
