technical

[Guest ray_turk]

i bought a 1939 buick i installed new battery amp meter shows it is discharging all the time any ideas

[Guest prs519]

Ray, I was thinking vintage cars, pre-alternator, will invariably discharge at an idle (which is why alternators took over, since they can keep up at an idle). If you

run your rpms up to 1200 or so, you should see a positive charge indication. Oldtimers depended upon the fact that people would be going down the road at a higher rpm

often enough to catch up with the discharge which occurs whenever the car is idling. Perry

[Mark Huston]

Another possibility is the battery is connected backwards. Some pre 50s cars had a positive ground unlike all of the cars of today. I do not know if a 1939 Buick is positive or negative ground. However, a battery connected backwards will cause the amp meter to constantly register a discharge until the battery terminals are reversed.

[Guest Grant Magrath]

Could be a faulty voltage regulator. Or a dirty generator comutator and brushes. Either way, see you over at the Pre-War forum!

Cheers

Grant

[Guest clare30]

You may have to polarise the generator to the correct positive or neg earth if it has just been rebuilt.

Clare30

[Ben Bruce aka First Born]

Another possibility is the battery is connected backwards. Some pre 50s cars had a positive ground unlike all of the cars of today. I do not know if a 1939 Buick is positive or negative ground. However, a battery connected backwards will cause the amp meter to constantly register a discharge until the battery terminals are reversed.

NEG GROUND.

Ben

[Curti]

OR, the wires are reversed on the amp gage.