VCCA Home Forums GENERAL DISCUSSION New User Forum battery voltage on 35 chev

when running engine i am getting 15 amps reading from amp meter.
However when i put a multi meter on the battery the voltage readings are erratic and not static. When engine is not running it reads 6.5 volts and cut out goes back to zero on amp gauge.
Why does this occur?
New Member.

Generator brushes bouncing? Bad section on the armature?

Welcome to Chevy Chatter! Glad to have you with us!

If your generator has a cut-out then your output of 15 amps is way too high. The ideal output of your generator would be somewhere between 8 and 10 amps. You can lower the output of the generator by moving the third brush back towards the engine. Your shop manual should show you how to do it.

Usually, erratic voltage is caused by a weak brush spring which causes brush bounce. Sometimes the erratic voltage can also be eliminated by re-setting the brushes with a brush stone on the armature comm., but most likely you will have to replace the brush spring on the brush causing the problem.

You can usually determine which brush is causing the problem by putting your finger on top of each individual brush and pushing down with your finger while the generator is running. If the voltage becomes constant when you push down on a brush then the spring on that particular brush is probably weak.

Note that some 1935 Austrailian cars had a voltage control. They also had a higher out-put generator.
The regulator was round and mounted on top of the generator.
Was also an option for US cars equipped with a radio.

He stated above that his generator has a cut-out. However, if, in fact, he does have a regulator on a high output geneator then the 15 amps output should be about right.

thanks for your answers the car has a cutout. i will move the third brush and see what happens.when the car is running at 30mph and over the amps dont drop it is constant 12 to 15amps

The output is too high. Move the third brush and see if you can get the output down to around 10 amps.

running at 10 amps reading still erratic with brushes held down but when i put meter negative to positve and positive to negative the reading is stable negative .also do you do timing with or without vacumm

The timing is set with the vac. line connected and the engine at a slow idle. The timing vacuum port in the carburetor is covered by the throttle plate at idle speed and is not getting vacuum.

Is there a generator number stamped into the Delco Remy tag on the generator or is the generator some other make because the car was either Canadian or an export model.

the number is 943j and car is canadian fisher body the cowl vent faces window when open

943J is the US generator for 1935 Standard models. It calls for 12 AMP charge with generator "hot". A conventional 3 brush gen. with a cut-out on top.

12 amps is the max. that you should go. You are better off setting the output at 10 amps.

changed it to 10 amps this morning thanks

Cool! You did good!

I wouild say 10 amps on the ammeter would be close to 12 at the generator because the ignition system is drawing about 2 amps with the engine runnning.