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Electrical strangeness with my 91 VW - what does this sound like?

First let me say after extensive testing and replacement of the starter, a relay, and recharging the battery, the car is running today; however, I'm not sure why. I could conclude that it was the starter solenoid, but I want to be sure.

1) The problem started when I was driving. One second I'm driving and the next there is no power at ignition (ON or START); like a light switch going to off. And after I got it home, the car acted like this: when the ignition switch was turned to the ON position, the instrument cluster had power. When it was turned to START position, the cluster went dead.

2) I have the Robert Bently Service Manual. I used this to test the various components and decided the starter and solenoid needed to be replaced. Yet, after I replaced the unit the problem persisted. At one point before I replaced the starter, the car did start. I got about 5 feet and it went dead again.

3) Then I started a through examination of the electrical system. I tested all the Fuses. I tested the Starter Switch. I tested continuity of the Wires from the Starter Switch to the Fuse/Relay panel. Finally I replaced one of the two relays in the circuit; One is called the Starter Interlock, and the other is called the Seat Belt Warning System. I replaced the first because it is only 12$ and avoided the second because it is 80$. However, these seemed unlikely causes because there was no power. According to the current flow diagram the Ignition Switch gets its power directly (without a fuse or relay in between) from the Fuse/Relay Panel to terminal 15 of the Ignition Switch.

Thats the low down. Operational= T+1.

My question, does this behaviour sound typical of any components in the electrical system?

Reply to
xtian
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Sounds typical of bad battery terminal/cables, or bad ignition switch.

Reply to
Ashton Crusher

Since it's a problem common to both the starter and the ignition, it's probably something common to both - maybe the ignition switch.

Reply to
dsi1

Could be:

  1. Starter is a dead short, pulling down the battery.
  2. Ignition switch is bad
  3. Battery is nearly dead.

Number three is the most likely one, and to rule it out you need to check the battery voltage unloaded and loaded.

That's interesting. What was the battery voltage you got? When it went dead, did the instrument lights go out as well?

Neither of these are likely to be the problem, and they can both be jumpered over for testing purposes.

What battery voltages did you see?

So far the battery is number one on my list, but without knowing the voltage on the battery, I can't be sure.

And the battery COULD be dead because of a bad alternator too. The voltmeter will tell you for sure.

--scott

Reply to
Scott Dorsey

Lets see if this describes the problem. You were driving along and the car quit. You then did a a whole bunch of stuff that did about as much good as mumbling incantations. Then you decided to charge the battery. After doing that the car started like it usually does.

Is that what happened?

-jim

Reply to
jim

Bad battery cable. They get corroded and stop passing current. When you moved them around they connected up a bit better and the engine runs.

I would also have the alternator tested. Most of the newer units do not like it when you disconnect the battery while they are in operation. It tends to blow out a couple of the diodes and then they don't charge.

Reply to
Steve W.

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