Electrical: its not the alternator or the computer
#1
07-21-2012, 12:15 PM
Electrical: its not the alternator or the computer
I have a power drain in my 98 Grand Caravan when the motor is running.
Several days after having the battery and starter replaced, the battery light started coming on. After driving a little longer the radio would black out and the ABS light would come on. Soon the battery would drain further... causing general havok with the remaining system functions including gear shifting, instrument failure, and ultimately the van will stall out, leaving insufficent power to even run the flashers effectively.
I have replaced the alternator (twice), and had the computer checked out (the unit next to the battery). The auto computer repair specialists said the unit bench tested okay (and also in a vehicle) and that the internal voltage regulator was not the source of my problem. An "on vehicle" alternator test indicates only 8 to 12 amps of charging at the battery, insufficient to maintain the current needed to run all the systems. But when removed and bench tested at the parts store the alternator passes. The batterty does NOT drain when the car is shut off.
I can put it on a charger before short trips, but use of headlights and/or AC could leave me stranded in less than 25 miles, so this is not an acceptable bandaid. The dealer gets it back next week although their tech couldnt isolate the source after several hours the last time it was there. Aside from an occasional flicker from the dash lights... all other systems seem to work correctly when the battery is charged. Are there wires or systems I should check first? Likely system culprits that the caravan is known for having shorts, excessive draws or grounds? This has been going on for over 2 months.
Several days after having the battery and starter replaced, the battery light started coming on. After driving a little longer the radio would black out and the ABS light would come on. Soon the battery would drain further... causing general havok with the remaining system functions including gear shifting, instrument failure, and ultimately the van will stall out, leaving insufficent power to even run the flashers effectively.
I have replaced the alternator (twice), and had the computer checked out (the unit next to the battery). The auto computer repair specialists said the unit bench tested okay (and also in a vehicle) and that the internal voltage regulator was not the source of my problem. An "on vehicle" alternator test indicates only 8 to 12 amps of charging at the battery, insufficient to maintain the current needed to run all the systems. But when removed and bench tested at the parts store the alternator passes. The batterty does NOT drain when the car is shut off.
I can put it on a charger before short trips, but use of headlights and/or AC could leave me stranded in less than 25 miles, so this is not an acceptable bandaid. The dealer gets it back next week although their tech couldnt isolate the source after several hours the last time it was there. Aside from an occasional flicker from the dash lights... all other systems seem to work correctly when the battery is charged. Are there wires or systems I should check first? Likely system culprits that the caravan is known for having shorts, excessive draws or grounds? This has been going on for over 2 months.
#2
07-22-2012, 02:47 AM
Professional
Test the alt while on the van. Follow the wires and keep testing them, every few feet if you have to. Find out at what point your loosing your power. I believe your van has a relay that gives the "ok" to charge the battery. If its not a relay, its some device, cant remember exactly due to it being Saturday night right now. You could just have a bad alternator,although I seen you have changed it twice already.