Hi everyone,

I have a strange problem. I had to replace my starter solenoid because I broke off a connection while removing the starter. After installing the new solenoid I reinstalled the starter but could not start the car. I rechecked the starter and discovered that the solenoid got really hot. I removed the starter again and did some bench testing.

Starter itself is working fine. Starter with the solenoid connected does not work and the solenoid simply gets really hot.

Here is the strange part: I tested the solenoid itself and when taking it on and off I forgot to put in the spring once and without the spring everything works fine. With the spring installed it shorts out. I also retested with the old solenoid and I get the same behaviour.

I feel like it might be something stupid on my end but I can't figure out what is wrong. Anyone got an idea? Thanks!

 

The observations indicate
1. Maybe there is a drop in voltage in the wire (thin wire)from the ignition switch to the starter solenoid terminal to activate the solenoid, ie less voltage than supplied at the starter terminal from the battery (fat wire). There is insufficient voltage to pull in and hold the plunger compressing the spring (resistance) so the plunger cannot not travel to make contact with the contacts to close the circuit to the starter windings.

Can use a volt/ohm meter to test or run a separate wire directly from the positive battery terminal and just touch the solenoid terminal connector for the thin wire.

2. Or there is a mechanical issue with the solenoid plunger connected to the lever to engage the starter gear to the flywheel. There is too much friction or binding or misalignment of the solenoid plunger adding too much force to overcome with the spring installed to close the starter circuit.

3. The solenoid getting hot is the current flow through the pull down and hold coil wiring generates heat.

 

Bump; what is the outcome?

 

Hi! Thanks for your reply. I did some more bench testing after writing the post and I feel like it is something in the direction of your no. 2. I was wrong to assume that there is some kind of shorting happening. Actually it seems like the magnetic switch can’t engage and pull down the lever in the starter when the magnetic switch is bolted to the Starter so it just gets hot instead. With the switch disconnected I can get it to engage but only without the spring, so when the plunger is already almost fully in. Same behaviour with the old and the new magnetic switch. I tested it with the car battery and a 12V lab power source. My battery read >12V when testing.

I got really frustrated and ordered a new starter but it will be some time before I can put it in the car to test it.

 

Take a deep breath and calm yourself. Diagnostic evaluation can be laborious and stressful, but less stressful on your pocketbook.