Post by azdesertrhino on Sept 5, 2006 10:08:08 GMT -5
I've read as many posts as I can find regarding charging problems but still have a few questions.
94 XJ 4.0 - Not charging battery. Had generator bench tested. Checks out with same numbers as a new one.
Tried a new battery. Voltage drops when I start engine and continues to drop. Battery voltage recovers after engine is shut off.
Checked and cleaned all grounds, connections, terminal etc.
Regarding reading the voltage at the terminals on the back of the generator? Can someone explain the actual readings between the different terminals.
Is there a way, as a test, to bypass the PCM voltage regulator before I buy a new PCM.
Took voltage readings. The numbers at the field terminals are telling me something is wrong, I'm just not sure what. Here is what I found.
Battery voltage - engine off - 12.6 volts
Engine running - lights off - 12.24 volts
Engine Running - Headlights on - 12.08 volts
Voltage across field terminals - engine running - 12.04 volts
Lying on carport, looking at back of generator. Engine running.
Right field terminal to ground - 12.08 volts
Left field terminal to ground .033 volts
B+ Terminal to ground 12.17 volts
B+ terminal to left field terminal 12.17 volts
B+ terminal to right field service terminal .012 volts
This morning, disconnected wires from field terminals and checked continuity. Had approx 5 ohms. Reconnected stuff, started engine and thing started charging. Started engine several times and now it quit charging again. Same basic scenario as above.
Don't want to just start changing parts. If I can't get it figured out I'll have to take it to a shop.
94 XJ 4.0 - Not charging battery. Had generator bench tested. Checks out with same numbers as a new one.
Tried a new battery. Voltage drops when I start engine and continues to drop. Battery voltage recovers after engine is shut off.
Checked and cleaned all grounds, connections, terminal etc.
Regarding reading the voltage at the terminals on the back of the generator? Can someone explain the actual readings between the different terminals.
Is there a way, as a test, to bypass the PCM voltage regulator before I buy a new PCM.
Took voltage readings. The numbers at the field terminals are telling me something is wrong, I'm just not sure what. Here is what I found.
Battery voltage - engine off - 12.6 volts
Engine running - lights off - 12.24 volts
Engine Running - Headlights on - 12.08 volts
Voltage across field terminals - engine running - 12.04 volts
Lying on carport, looking at back of generator. Engine running.
Right field terminal to ground - 12.08 volts
Left field terminal to ground .033 volts
B+ Terminal to ground 12.17 volts
B+ terminal to left field terminal 12.17 volts
B+ terminal to right field service terminal .012 volts
This morning, disconnected wires from field terminals and checked continuity. Had approx 5 ohms. Reconnected stuff, started engine and thing started charging. Started engine several times and now it quit charging again. Same basic scenario as above.
Don't want to just start changing parts. If I can't get it figured out I'll have to take it to a shop.