[Christian Hunt]

So my truck has been dying over night and I have to jump it every morning it runs fine while it is running but will die over night even with it plugged in when it's cold also while I was gone my buddy was coming by to start it everyday and said one day my edge insite was flashing on and off I don't know if this could be alternator or pcm or something else

 

[RT]

Start with the batteries - charge them completely and then have them load tested individually at your local parts store. Next, check your voltage while running. It should be in the upper 13s to low 14s. If both of those are good, then you may have a parasitic draw draining your batteries overnight. There is a test mechanism to isolate that, but we'll get after you try the first two things.

 

[Christian Hunt]

I have had them both fully charged and test individually and they still are dying on me the guy I bought the truck from actually had the alternator replaced before I bought it and that was a year ago and the volts sit at 13.8 to 14.2 while running unless I have the heat on then while it is idling it drops to 12.8 to 13.0

 

[DENNY]

Starter is going bad. Do a search common problem.
DENNY

 

[RT]

Hey Denny. Could you explain to me how a bad starter causes his voltage to drop to 12.8 when he turns the heater on? I'm just not following that circuit in my mind....

It would seem to me that if your alternator can't keep up with even a blower motor, you may have isolated the problem.