Went through a spell recently where the battery died, put in a new one that died in a few days, put in a new one, had battery and alternator test good. Switched out a starter relay and found a loose grounding wire coming off the starter. That seemed to fix all the issues for about 30 days but now the battery light is intermittantly coming on after about 15 minutes of driving. Stays off after I have parked it for a bit but when I drive again it comes back on after about 15 minutes? Anybody have an idea what to look at. I really don't want to take it to a shop.

 

Use a volt meter to check voltage at battery engine off for 20 minutes Should be 12.5-12.9V.

Start engine, rev to 2000 rpm and check voltage. Should be 13.5 to 15.1V.

Make sure the is not a parasitic drain on the battery when the car is parked.

 

Ok will do. What can cause a parasitic battery drain though?

Cp

 

Issues such as a trunk light not turning off when the lid is closed, an aftermarket stereo amp or alarm system not turning off. A problem with the alternator can cause this also. The internet has info on this issue.

Sometimes a circuit board fails and causes this. Happens on much later year cars having lots of circuit boards.