TheSamba.com :: View topic - [71 automatic] Starter solenoid issues, won’t crank when hot

Thu Aug 20, 2020 7:08 pm

I’ve been having this issue off and on every summer but lately it’s gotten worse. Sometimes after driving for awhile or just random intervals my squareback decides not to start. No cranking or anything. Just a faint click from the starter, dimmed dashboard lights, and the battery drains slowly. Yet every time I’ve tried jump starting it turns over fine, even though my battery rests at 12.7V and 14.6 running, my recent fix is giving the starter solenoid a light tap with a hammer and that seems to do the job but I’d rather not make that a consistent task and risk damaging something. it’s happened more often when it’s hotter than hell or it’s been sitting in the sun. It doesn’t seem like it’s my ignition switch or neutral saftey switch so I’ve nailed it down to presumably a dirty/rusted starter solenoid.

My question is does anyone have experience dissassembling the solenoid and cleaning it? Cause from what I’ve researched it sounds like it can be done, and I’d rather do that than drop $300 on a new starter if I don’t need to lol. I just wanna know how difficult it can be and what I should look out for or if maybe I’ve missed something here. Thanks!

Fri Aug 21, 2020 1:38 am

Braeska wrote: dimmed dashboard lights, and the battery drains slowly.

Just to make sure, is this when you are trying to start it?

The Bentley doesn't have a procedure for repairing a solenoid, just testing it. What I would like to know is what is the voltage at the solenoid activation terminal, when you are trying to start it, but it doesn't turn over.

You have to remember that all of the wires are over 40 years old. Over this time the wire's resistance slowly increase, which can lead to a voltage drop. Also the resistance of copper wire also increases, as temperature increases. Thus another voltage drop.

In the Type 1 world, they place a ford truck starter relay before the VW solenoid, as kind of a band aid fix (search Hot Start Relay). However, if it was my car, I would do a full electrical check, before dropping $$.