1974 Super Beetle - Won't Start

[Sluggo]

I've narrowed it down to either the starter switch or the solenoid. I think it's the solenoid because if I whack it gently with a hammer a few times it will start (sometimes). Any suggestions on how to make sure before I buy & install a new one?

[dtrumbo]

Turn the key to the 'on' position and then AFTER MAKING SURE THE CAR IS IN NEUTRAL AND THE HAND BRAKE IS SET, crawl under the car and jump the terminals on the solenoid. If the car starts, and you can repeat this experiment multiple times with the same result, the solenoid is fine and either the switch is bad or you have a loose connection.

Since you say the hammer-whack does the trick sometimes, I'm suspecting a sticky solenoid, or just as likely, a loose connection on the solenoid. Make sure they're all clean and tight before you spend any money.

[Amskeptic]

Turn the key to the 'on' position and then AFTER MAKING SURE THE CAR IS IN NEUTRAL AND THE HAND BRAKE IS SET, crawl under the car and jump the terminals on the solenoid. If the car starts, and you can repeat this experiment multiple times with the same result, the solenoid is fine and either the switch is bad or you have a loose connection.

Since you say the hammer-whack does the trick sometimes, I'm suspecting a sticky solenoid, or just as likely, a loose connection on the solenoid. Make sure they're all clean and tight before you spend any money.

Bad solenoids, unfortunately, can be inspired to behave after electro-shock therapy. There is no definitive proof of anything with the "bridge the contacts" method of starting the engine. It merely gets the engine running.

If the no-start occurs when the engine is warm, and it starts reliably when cold, you can be sure the solenoid is the culprit. The BobD gave me a no-start at a gas station in New Mexico at 1:15AM this morning. Electrical connections and switch are pristine. Solenoid.
Colin

[Sluggo]

Voltage regulator. Saw an article where the guy mentioned the same issue. The VR is going out and not charging the battery enough to start, but it is charging enough to show 12volts. It's just barely under the line. Jump start & replace the VR and all is good.