I've got a '96 Town and Country minivan that has had repeat occurrences of the battery being dead. It has been very infrequent, and has sometimes been after as short as being parked over night.
The battery is not that old, and I don't want to just shotgun parts at it.
I removed, cleaned, and reinstalled both the chassis and engine grounds, those can be ruled out.
I checked for parasitic draw, I'm reading anywhere between 10mA and 30mA, completely reasonable. I've also checked this several times over a 24hour period with no change.
I figured I'd try attaching an oscilloscope to the alternator to see if anything obvious would show. I'm quite the novice at using an oscilloscope, so please bear with me.
I attached Ch1 probe to B+ on the alternator, Ch2 probe was connected to chassis ground. The ground clips from Ch1 and Ch2 were coupled together and attached to chassis ground as well. The van was started and loaded with the headlights on bright, and rear window defroster turned on. All other loads were turned off(radio, HVAC fan, etc).
What I got was complete chaos... I was certain that I did something wrong. Here's the results:
The battery is not that old, and I don't want to just shotgun parts at it.
I removed, cleaned, and reinstalled both the chassis and engine grounds, those can be ruled out.
I checked for parasitic draw, I'm reading anywhere between 10mA and 30mA, completely reasonable. I've also checked this several times over a 24hour period with no change.
I figured I'd try attaching an oscilloscope to the alternator to see if anything obvious would show. I'm quite the novice at using an oscilloscope, so please bear with me.
I attached Ch1 probe to B+ on the alternator, Ch2 probe was connected to chassis ground. The ground clips from Ch1 and Ch2 were coupled together and attached to chassis ground as well. The van was started and loaded with the headlights on bright, and rear window defroster turned on. All other loads were turned off(radio, HVAC fan, etc).
What I got was complete chaos... I was certain that I did something wrong. Here's the results: