Well I got a check engine light and so I wanted to see what was wrong, So I did the little key dance and got a code 46 which is for charging system voltage is too low, well I put my multimeter onto my battery and when the truck was sitting not running the battery was showing 12.09 volts and then running it dropped to 11.89 or so. Well from what I understood it should be higher so I think that the alternator is going out. So long story short I went and got a different alternator at a wrecker and installed it. Well I have yet to get the light again but my readings on the multimeter is the same as before instead of the 14 or so volts that I figured there should be. Well I am trying to rack my brain to what could be causing this and thought I could wrack your brains as well? Any help is appreciated...

 

A good range for an alternator is 12.8 or so up to 14v. So if the new/used one is still at 11.89 you may have got another bad alternator or the voltage regulator in the PCM has failed. Or you got bad wiring. Most autoparts stores will test it alternators for free.

 

If it's the PCM you can get a remote regulator

 

Well I have an update on this, I tested the alternator and it was all working fine and so I went to the wiring next and when tracking wires I found a thick black wire with a quick disconnect coming from the alternator and it was unplugged. I found the other half of the wire and plugged it all back up and guess what now the alternator is charging again. So I attached it with some zip ties so that it wont come undone again and now she is running like a charm again.