Does anyone have the diagram for the voltage regulator circuit? I keep having to boost my truck to get the alternator to have output because the exciter wire seems to be a pos.

 

There is the charging/starting diagram. I know it's not everything u need but hope it's a start

 

Have u checked the voltage at the starter and at the fuse box? If you truly believe it's the internal regulator, you can get a rebuild kit. I would check the voltage at the alternator, then at the battery. If the alternator is putting out good and not getting to the battery, check the voltage at the starter. The solenoid wire can get corroded down there and cause issues. Then check the voltage at the fuse box under the hood. You should be getting in the mid 13volts to 14 volts

 

It's a brand new alternator. Checked on the bench and it's fine. It's also fine once I bump the reg with 12v. Charging my battery at 14.4v. It's just not being told to send out voltage through the alternator

 

Not sure what you mean by "boost"? Do you mean you have to rev engine to get it to start charging? Or are you jumping voltage to the exciter wire?

Anyhow...

What type of voltage reading are you getting at the exciter wire, with ignition in "on" position and wire disconnected from alternator? Should be just about battery voltage or slight less (11.7 to 12.4).

Looks like fuse 27 would be a good place to start, if you have no voltage. If it is below suggested values, then I'd check ignition switch and connection, if those check out good, then work your way towards the alternator, checking for corroded/broken wire.

Brian.

 

Actually, I had a weird experience on my Porsche after replacing the alternator. Brand new alternator, exciter wire had 11.7 volts with key on and wire disconnected. However, I'd connect everything up, start car and it wouldn't charge. So, on and off the alterntor went for a couple days, having it bench tested once at Autozone (checked out okay), installed...same problem, no charge, then removed again and had it bench tested at a "real" alternator shop...checked out okay.

Well, I was just about to go crazy...because everything checked out good from ignition switch to alternator. But, then I finally decided to connect the exciter wire...while I was under the car with it running. As soon as I touched the exciter wire to the post...it started charging. I was like???...what the hell. So, I put the nut on and tighten it up (still running)...and it stopped charging. Checked voltage at the exciter wire and there was none. Again...what the hell.

Went to take the exciter wire back off...and as soon as I turned it an 1/16 of a turn...it started charging again. The terminal post that goes through the housing of the alternator was turning enough that it grounded out the exciter wire inside. So, off came the alternator one more time, took it apart...and whoever had assembled it, had the internal wire to close to the housing and when you tighten it...it came in contact with the housing.

Just thought I'd pass this along, since you said it was a new alternator. But, as you can see/read...this doesn't mean much sometimes.

Brian.