Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: 39 Limo on January 11, 2010, 02:56:46 AM

Title: 39 cadillac V8 starter problem
Post by: 39 Limo on January 11, 2010, 02:56:46 AM
Hey Guys 
 
Here's the problem, after starting the motor and then shutting it down. My stater button will not work unless i either keep the key off and engage the button witch engages the start for a very, very brief second and then turn the key to the on position and engage the start button then i get the "normal" start. Or sometimes i have to "Ground" one of the terminals on the start button and then the normal start will occur. Any thoughts? 
Title: Re: 39 cadillac V8 starter problem
Post by: Doug Houston on January 11, 2010, 09:24:56 PM
From what you describe, it sounds like possibly, the starter switch (The button switch) on the dash might be working intermittently.  The starter switch on the '39 cars is accessible from below the dash, so with the ignition switch turned "on"you should get a voltage reading on one of the terminals. If there is voltage there, then press the start button, and see if the other terminal becomes live. If so, the start switch itself, is good.

You can test the starter and the solenoid on it, by connecting a clip lead to the hot (Negative) battery terminal, then touching the other end of it to one of the small terminals on the solenoid. Have the transmission in neutral, and the ignition turned off before you do this. One of those terminals will do nothing, but the other will cause the starter to crank the engine. If the starter doesn't work this way, the trouble will be in the starter itself, or in the solenoid.

To test the starter motor, get a large screwdriver, and momentarily short the two big terminals on the solenoid together. The motor should run, but not engage with the flywheel.

Another possibility is the connection from the generator regulator that grounds the starter solenoid. On the pre-1940 cars, there was a relay in the generator regulator that grounded the starter switch circuit, when the engine wasn't running. Those relay contacts could be contacting intermittently.