My 1941 model 41 doesn’t start with the depressed gas pedal?

[Howard Boyle]

My ‘41 model 41 won’t start with the gas pedal.  It did do it occasionally but has stoped.  I have a button installed to activate the carburetor switch.  Is there a switch relay connected to the pedal?  What am I missing?  I had the carburetors rebuilt and it runs great but the starting bugs me.

[Business_As_Usual]

Hopefully you have already checked and cleaned the battery terminals, the connections at the starter and solenoid.  I recently had the same problem. Turned out the positive battery connection was not on the solenoid first and I found it arcing at the connection. Put the battery cable on the solenoid first and then the other wire and haven’t had any problems since. Hopefully you don’t have the original wires on your car, because if you do it can be anywhere in the wiring.  Also check the connection at the ignition switch and at the A or Gen. terminal at the voltage regulator.  Hope this gives you at least a starting point to find the problem. Good luck. 

[Howard Boyle]

Thanks I’ll give it a try.

[Business_As_Usual]

Could also be the starter or the solenoid.  You can pull it off the car and bench test it. I took mine to a place in Galesburg, Illinois.  He went through it, cleaned and serviced it for 40 bucks. Unfortunately he retired and closed his shop about 3 months ago. 

[Bloo]

There is a relay on the back of the starter solenoid. The relay coil "floats" (isn't grounded) and has terminals for 2 small wires. You must provide power on one terminal and ground on the other for the engine to crank.

 

The Buick will have a mechanical throttle switch and a vacuum switch in series to provide power. Both switches must be on to crank the engine. The throttle switch is on whenever the gas pedal is depressed and the vacuum switch is on when there is no vacuum (engine not running). I believe by 1940 one(?) or both(?) of these switches were integrated into the carburetor. It varies by year. In the mid 30s, both switches were in a separate assembly that screwed into a vacuum port in the intake manifold, and also connected to the throttle linkage.

 

The ground for the little relay has been provided in different ways depending on year. In 1940 though, the wire from the ground side of the relay is connected to the GEN terminal of the voltage regulator, and "finds" a ground through the generator windings and brushes. In theory bad brushes not making a good connection could cause the car not to crank. If you test by grounding the terminal on the relay, be sure to disconnect the wire from the terminal before you do. The wire coming from the GEN terminal will become HOT as soon as the car starts and the generator starts working!

 

 

Edited March 17 by Bloo (see edit history)