Hello all, this problem has been posted many times before and after hours of reading I have come to no conclusions for my specific problem. Recently after getting my AC recharged with freon I have noticed a fluctuation in my voltage reading on my dash. When I turn the AC on and the fan on any speed the volts drop down to about 12.5. If I turn on rear defrost, headlights, wipers, everything. The volts drop to about 9.2. If I am just running the AC and fan on high and then turn it off, the volts rise back up to normal. Same for if I have all accessories running, turn them off the volts spike back up to about 13.8 volts. Before now I have never had much fluctuation in my volts with accessories on. I tried a different battery that is brand new last year and fully charged with the same result as the original battery. Grounds could be a possibility but my problem just started one day, not gradually, which hints to me that maybe it isn't a ground. I plan on testing the volts directly from the battery posts with a good tester, I have read the on board volt meter is not a true reading.

Update: I tested the volts at battery terminals with no load, 13.6 with full load at idle was 12.6, gauge on board read 9 volts. Then had a bad belt screeching

Update again: I removed the low pressure AC sensor and had considerably less voltage drop when turning the fan on, I also could turn my belt 90 degrees, I will be tightening tonight hopefully then return back


Any ideas will be greatly appreciated and I will update my post as I try new things. Once again, thanks for any help!