VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 blown'in bulbs.....

Hey all....
for some reason this year, I've blown both headlight bulbs and tail/brake lights bulbs. My generator is showing an increase in amperage for some reason. If someone could walk me through the way to adjust the 3rd brush, I would appreciate it.
thanks,
Cliff
p.s. I checked my books and there isn't (to me) a thorough explanation on how to do it.

I believe that the repair manual shows how to adjust the third brush. At any rate, remove the generator cover band. On the commutator end frame (rear of generator) you will see a 10-32 round, slotted head screw. Untighten it a few turns. Then, move the generator brush and arm that is on the top of the generator (right in front of the generator through bolt) towards the engine to decrease the generator output (moving the brush towards the fender increases the generator output).

Adjust the third brush so that your maximum output is 12 amps. After adjustment, tighten down the 10-32 screw and replace the generator cover band.

You might also want to check the generator voltage as well. With the car running, hook up a volt meter to the generator and check the voltage output. The voltage should be between 7.5 volts and 8.2 volts.

Is that 12 amps at idle or at higher rpm's?

It is the voltage that will blow the bulbs not the amps. The amps would be set at a fast idle, or above.

The output of 12 amps is at 1,700 RPM generator speed. Keep in mind that the generator RPM is twice that of the engine RPM.

Thanks Dog,you taught me 2 things in 1 day!My school teachers couldn't even do that!

I would think that the vehicles Groundings should also be suspect. Al W.

Thanks JYD. I will check that on thursday (I have to work tomorrow).

67... Why do you say the ground should be checked ? Just want to learn 2 things today as well.

Cliff

Electricity passes through the devices that operate from it. The Voltage must be able to return to its source via the Ground or things can go wrong. Your Battery not only starts your engine, it acts as a Ballast to allow veriations in Voltage without stray current damaging components. It is not likely that you have a bad ground since bad grounds usually cause component inoperation or poor performance. That said, when we reach for an illusive fix, we check everything. GOOD Luck, Al W. BTW, did anything glow brighter than normal?

67vetteal
Yes, I learned the hard way how the battery in my 31 acts as a ballast when I disconnected it while the engine was running. I not only burnt out all the bulbs but also the ignition points. I won`t be doin that again anytime soon.

hoppy

Yep, without the battery in place to act as a ballast, the generator will put out high voltage.

I better check my battery and grounds....

and yes my tail/brake light bulbs did seem brighter.

My very first car was a Model A roadster. When I hit a bad bump the ground strap came off the battery and blew out all the bulbs that were on. It also fried the amp meter, too. It was at night and I failed to see that bump and the headlights were on.

Hey all
I adjusted my generator (thanks JYD) and everything there is good. 2 new bulbs in the headlights and the right one is dim and the left is bright. Grounds are good so I suspect maybe a deficient bulb on the right.
I'll keep workin' on it.
Cliff

Turn the right bulb 180 degrees and see if it is still dim. If so, you probably have a bad ground to that light.