Vacuum erratic when electric fans turn on

[forestb]

Originally Posted by pjmoreland

When the engine is running and the fan is on, do you get the same voltage reading at the red wire on the back of the alternator as you get at the distributor bat+ connector?

EDIT - I skimmed through all of the posts on this thread. Did you take RustyPile up on his offer for a phone conversation? Is your distributor voltage still jumping around? How is the power wired to your distributor? If you follow the wire from your distributor to the location where it ties into electrical system, is the voltage jumping around at that connection as well?

I have not checked my voltage at the alternator with the fan running. When the fan is not on I am reading 14.7 volts at the alternator and 14 volts at the distributor bat+ connector.

No I have not taken rusty pile up on his offer yet. I was afraid that by the time I finished talking to him he would have me rewiring my entire vehicle

I am assuming that when you are referring to my voltage jumping around you mean when I said that it goes down to 3 volts and then back up t around 14 and back down again and that you are not referring to the drop when the fans come on. I think it was because I was not finding a good ground with the negative probe.

With all that being said, my voltage at the distributor is not still jumping around.

My distributor wire connects to the plug in back of the ignition switch. I have not tested the voltage there. I should. That my be a good indicator as to whether the purple wire spliced in from the AC is causing the voltage drop at the distributor bat+ connector.

I am sorry to say that I will not be able to do any of these tests until Saturday.