Why does my 74 VW Thing only crank once or twice and never start except when pushed even after its run for thirty minutes or has jumper cables attached?

Answer 1

Do the easy stuff first... Check your power and ground connectors on the battery. On the body also. Check the starter wires to make sure they are clean and have a good connection. Clean the battery posts and the connectors until they are bright and just unbolt/unscrew the ground strap to the body slightly and wiggle the wires around then retighten. You can still get volts from the battery with dirty connectors but you won't get the AMPS needed for the starter. == Engine running check charging voltage with a digital meter.== If it's below 13.2 VDC then you have a bad voltage regulator or generator. At rest battery is OK at 12.6 VDC (full charge) then you need to install a start assist relay. Get a bosch 30 amp spst relay from a friendly local autoparts store. Pull the wire from the key switch at the starter solenoid and connect it to the relay terminal # 85. Run a wire from terminal 86 to ground. Run a wire from terminal 30 to the heavy starter wire installed on the solenoid. Run a wire from terminal 87 on the relay to the solenoid lug that was originally inhabited by the key switch. I used VW #141951253B rated 12V at 40 A. I've got a better source for the relays you need to do this. In "How to Keep Your Volkswagen Alive" John Muir discusses using a Ford starter solenoid as a relay. You can get reproductions of Ford starter solenoids at Tractor Supply Co. These carry more amps than foglight relays do. But thinking about this more...I don't think it's any of the stuff we're talking about. I think the starter ITSELF is bad. It happens, especially on a 34-year-old car. Do this: Pull the starter and lift the back seat, so you can get to the battery. Make sure the battery's good--hook your voltmeter to it and be sure you've got at least 12 volts there. Now get about six inches of wire and crimp a push-on connector to each end of it. Push one of them onto the key-switch prong on the solenoid, and think of this as the switch wire. Hook your jumper cables up to the starter--negative on the battery to the mounting-bolt flange, positive to the left-hand bolt on the solenoid (the one you disconnected the battery cable from). Then touch the switch wire to the positive jumper cable clamp. Three things should happen; one definitely will. You are going to get a huge shower of sparks out of the switch wire where it's touching the clamp. It won't hurt anything, so don't freak out. You should see the shaft of the starter motor jump forward swift and smooth. And then you should see the shaft start to spin. What you probably WILL see is the sparks, the shaft move forward in a leisurely fashion if at all, and the motor not turn very fast if it turns at all. If this is the case, you have four choices. You can send http://www.mamotorworks.com $150 for a new one, crawl around in a junkyard for two days looking for one, have a local auto electric shop rebuild the old one for about half the price of a new one, or attempt to clean the old one. If you want to try to clean the old one, get some lithium grease, mineral spirits, electrical contact cleaner, rags and 600 grit sandpaper. You take the end caps off and wash them in mineral spirits, shine up the copper contacts on the "gear" end of the starter shaft with the sandpaper, very carefully (these are very fragile) clean the copper off the carbon brushes with the sandpaper, clean the shaft with the contact cleaner, let everything sit for a few hours to dry out, put the starter back together, pack the small cap at the very rear of the starter with lithium grease, and try the jumper cable and switch wire thing again. It will either work or it won't and it usually works about six times. I have done it when I was too broke to buy a new starter, but it's not really the preferred method--more of a patch. It'll work for about six months to a year and then you gotta rip into it again. My preference? New one if you can afford $150, rebuilt if you can swing that.