OK, I think my van is haunted.....

So here's the scoop. I replaced the ground cable in the battery box, cleaned the connection, etc. Still having the same problem. With all the fuses installed the signals are fine with the igniton just on (not running) as are the brake lights, headlights, and reverse lights. However as soon as you start the engine everything goes haywire. The left front signal works fine, but the right rear blinks very dimly. Same for the right, front is fine but left blinks dimly. Headlights work fine with the motor off but as soon as you start it the motor stalls. Same with the reverse lights. As long as nothing is on (fuses installed) motor runs fine. Revs and idles correctly. Checked all connections in the engine bay everything is OK. Only thing I can think of that I haven't checked is my starter connections but can't see them being a problem. All of the other engine connections are fine. During the rebuild these were the only connections I disconnected. Any ideas?

Reply to
westfaliaguy
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just forget about it. that should do the trick. cheers

Reply to
fullopiss

What changes when the engine is running ?

Only thing I can think of is the charging circuit. I would give that a good check over, maybe even disconnect it for a try. (if you ave an alternator I am not sure this should run disconnected so maybe disconnect the drive belt) Type 4 right ? If type 1 dont run it for long without the belt.

Rich

Reply to
Tricky

I'm not a bug/bus expert, but have troubleshot a lot of electrical problems. Here's my 2c:

A ground connection may have fallen off somewhere. You could use booster cables (just the negative side, leave the positive side to dangle) to make temporary connections from parts that should be grounded to a point you know is grounded (like the battery negative). When you make a connection that causes it to behave, you found your bad ground.

It could also be something I've seen once on a Saab where the alternator had a shorted diode - unusual, because they normally fail open. It caused AC to be injected onto the power rails and screwed things up royally, basically varying the 12V battery voltage between 8 and 16 volts. It can cause havoc with electrical components in your car, especially an ECM as this Saab had.

You will not see these AC variations with a DC voltmeter. To see the actual peaks, you'll need a scope. To see if you have AC superimposed on your 12V supply rails, set your voltmeter to AC, measure across the battery terminals. There should not be a significant AC component - there might be some, but it should not be in the order of volts. Most meters are not capable of measuring beyond 100 Hz so, if you have both a digital and analog meter, I'd compare the results.

Remco

Reply to
Remco

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