Have a friend with a 90 civic si. We are having a problem with his alternator wiring, was hoping that the HT wrench heads could give me a bit of advice.

When the car is off and the ground is disconnected, I am getting 12 volts through the alternator at all times. Looking through the Honda Service Manual, there should only be voltage when the ingition is on or the engine is running.

This problem is causing the alternator to drain the battery all the way dead. I am thinking that there is a short in the wiring somewhere, but not sure where to look. Any ideas???

 

it has to be grounding out some were along the wires and giving it juice, check that first.

 

Try removing the thick white wire from the alternator.
Test the wire for 12V - I think it's supposed to as that wire runs up to the shock tower fuse box on the passanger side.

Then test the lug on the alternator and see if is ground.

Maybe the alternator shorted internally and is grounding your 12V wire..

 

I have tried removing the thick (charging) wire from the alternator. I still get the 12v at the alternator. I also had the idea that the alternator is grounding out internally, but I am also worried that there might be additional problems.

 

bump

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kimo98GSR &raquo;</TD></TR><TR><TD CLASS="quote">I have tried removing the thick (charging) wire from the alternator. I still get the 12v at the alternator. I also had the idea that the alternator is grounding out internally, but I am also worried that there might be additional problems.</TD></TR></TABLE>

You get 12V at the alternator with the alernator disconnected and the engine OFF?