QuestionI have gone through 2 batteries and 2 alternators since October of 2006. I have had a device called a pastime (starter interrupter) in my van. my van died on me about a week ago and i had the battery and alternator checked, i was told the battery was good and that the alternator was bad. we changed the alternator and the battery was still not charging. the level that they got while checking it was an 11.9. I took the van and had the pastime taken out in case that would be contributing to the problem with the batteries and alternators. when i had the device taken out they noticed that the water pump was bad, they changed the water pump and belt. when i went to get the van they told me that they checked the charging system again and it was not charging in which it had the day before. What can be causing my van not to charge and hold a charge? What should I be checking for in order to fix it?
AnswerHi
I cannot believe that a simple charging problem cannot be diagnosed.
The PCM (Powertarin control module) is brain of this system.
It turns on and off the "L" terminal of the alternator which allows charging.
This data CAN be viewed with a good scan tool. Easy to read if the L term is on and off. On= charging. Off= no charging.
The alternator is next. It has an internal voltage regulator which regulated voltage thusly-
Closes below 11.20 volts or closes ABOVE 16.5 volts or CLOSES with a stopped condition (not spinning).
Opened all other times.
From the back of alternator the large red wire (Battery charging voltage)goes THROUGH a fusible link (rust colored) to the starter (Link is located VERY close to the starter). It from there it charges the battery via the positive battery cable.
If I was working on your van, I would make sure the L terminal data was ON. If it stays off at all times, I would check the 10A Ignition 1 fuse. If blown I would replace and recheck.
If not blown I would HIGHLY suspect the PCM as fault.
If it is ON and not charging, I would check the wire from the PCM to the alternator L terminal.
I would check the ground circuits MAKING sure the alternator is grounded well.
I would check the fusible link. I would check ALL battery terminals and ends, I would check ALL related wiring using a VOLTAGE DROP test.
Whats the Battery light doing? Is it on or off?
If off I would REALLY check the IGN1 fuse.
I Hope this helps.
I would also make sure that they are getting the proper alternator for this system. If you put a non computer controlled regulated alternator on one that is, the L terminal is in a different loctaion nad they WILL NOT charge.
Good luck
Pawl
