Frankie the Fink

One of the advantages of alternators is that they can charge at an idle; generators are not so great at this. So, depending on the load and how the V/R is adjusted...you may well see the needle go negative at idle. Not so sure that isn't normal behavior.

dplotkin

I think what he said was his needle moves between center and charge with his blinkers on instead of the other way around. Maybe his meter is wired backwards?


Dan

vettepoor

Dan - That is exactly what is happening that has me stumped. Needle drifts left at idle, as expected, except when blinkers are in use. I've checked for loose wires, and gauge is wired correctly. Maybe some corrosion in turn signal assembly could be causing this?

John

Frankie the Fink

Folks should be aware that the GM (and GM licenses schematics) have the ammeter wires reversed in the document...doesn't hurt anything but your gauge will read backwards.
Dr. Rebuild's schematics have them correct.

rich5962

Frank I believe the AIM is what shows the wires reversed. Fixed in the '62 AIM IIRC.

The wiring diagrams actually don't show proximity of their orientation.

dplotkin

I don't know that I'd let that bother me so long as its charging properly. My only guess is that you have a relay/timer type flasher unit instead of the stock thermal unit. The relay types can introduce reverse EMF (voltage) in the circuit each time the coil voltage collapses (bulbs flash off), just a guess. Look under the dash & tell us what kind of flasher unit lurks there.


Dan

Pilot Dan

Joe, it would be a good idea to periodically check the voltage at the battery with the engine running for a while (if the ammeter is doing strange things) just to be sure you don't have an overcharge condition which could damage things. Better to be on the safe side and it will give you peace of mind.

devildog

The indication is correct.

I drove it again today, all indication on amp meter and other electrical functions are normal.

Thanks

Joe

devildog

Just curious, what is the purpose of the big (thumb size) capacitor on the amp meter ?

Do not think that is a factor in our analysis, capacitor either works or does not work...just curious.

Joe

Frankie the Fink

Does that mean which ammeter terminal individual wires go to?
If so, I agree

Frankie the Fink

The only capacitor on these cars that ISN'T for radio noise suppression is under the distributor cap

rich5962

Yes, sorry if I appeared to add some confusion to the explanation. Next time I'll try to eschew obfuscation with a simpler answer.

Frankie the Fink

Yeah - don't be getting too big for your britches down there in the hinterlands of Florida, not like you live with us highfalutin' folks near Disney

Anyway, I'm back to the gauge/wiring on this problem. IIRC Devildog has a 500 horsepower beast crammed in his '61. I'm thinking during his high-RPM runs and when he's got the car bouncing a little starting up that monster; his intermittent problem occurs. I think a complete wiring chase down is called for and perhaps a gauge swap. Meantime I'd pull all the fuses and start it up cold just for grins and see if the problem occurs...

devildog

I have driven it several times with the old V/R reinstalled and after tightening the wires and connections. All is functioning properly, I will watch the amp meter to see if it upsets again.

Frank, now lets not exaggerate my little SBC engine does not make 500 hp, it dynoed only 496 with 470 tq. It does not actually vibrate when I get on it, but does sort of try to do a climbing right turn in the old C-1 frame.

Joe