alternator charging fluctuations

**Booba5185** · 05-15-2015

The PCM doesn't have communication with the alternator, so it's nothing too sophisticated. All it does is supply the +12v to the regulator for field voltage. If anything, the PCM monitors the system voltage then turns the regulator on or off based on that voltage.

**J57ltr** · 05-15-2015

Originally Posted by chrsmi1

Not a great picture, but zoom in and you can see it better.

how often are you logging I set mine for every 5 seconds since that was the longest time I could use and I was going on a 2 hour drive. My logs from going to Shreveport are worthless since I didn't know I had to pick what to log. I do have a bunch of screenshots of the app in action, several times I reset the min-max after I took the pics. I do have some log files from my trip from Shreveport to Ft. Polk and back. I need to get them off of my phone. My neighbor is an IT guy and I'm going to ask him to make it into a graph (I'm computer stupid), I just logged control module and at the BAFX (about a 1V drop).

I did end up verifying that the Voltage at the fuse panel and was within .1V I also measured at the ALDL and it was the same within .1V.

Booba,

It really doesn't matter whether the signal is serial/0-10V/20Ma current loop/PWM or simply on off, the PCM controls the alternator.

**Booba5185** · 05-15-2015

I know, I'm just saying it's nothing too complicated. We need to get some tuning guys to see if there's anything in the tune for the alternator. Then we'd know for sure.

**J57ltr** · 05-15-2015

Ok here's one chart. I'm not real sure how long it is but I believe it spans a few hours. This is from a warm start. I went to my hotel packed up changed clothes and left. Got on the freeway doing about 55-70 during this time