I installed a new high capacity alternator (~ 100A) last Sunday and drove the '88Xj to work all week. I drove in the garage Friday afternoon and no accessories were left on. I tried to start the car early this afternoon and no response; not even the slightest sound. I put my DMM across the battery terminals and read 50-60 mV. What are the likely causes of this?
To the best of my knowledge B+ is left on for the IAC motor at engine shut down and this is timed to shut down but, I forget the duration of this timer.
I jumped the Xj with a 18000 mAh booster pack and it had to work to get the Xj started. I drove the Xj around for ~50 minutes and the analog charging system gauge never dropped below 15 VDC. In general, I kept the engine above 2000 rpm.
When I returned to the house I let the engine idle while I went inside to get the trickle charger (This was a guess - my 2A/10A/55A charger failed in 2016 and I have not replaced it. I would not expect driving the Xj for 50 minutes would provide me with much battery capacity.). I connected the trickle charger to the Xj battery cables at the terminals, plugged it in the 120 VAC outlet and shut the engine off.
In walking around the rear of the car I realized I was in the garage far enough to close the overhead so, I climbed in the Xj driver's seat and started the engine...no issues...easy start (for an Xj w/OEM single hole injectors!) just like all week. Moved the Xj forward a bit and shut the engine off. I disconnected the Xj battery cables and connected the trickle charger directly to the battery terminals. The initial response of the trickle charger was nothing (green LED). It has charging the battery for ~1 hour (RED LED).
Any ideas?
To the best of my knowledge B+ is left on for the IAC motor at engine shut down and this is timed to shut down but, I forget the duration of this timer.
I jumped the Xj with a 18000 mAh booster pack and it had to work to get the Xj started. I drove the Xj around for ~50 minutes and the analog charging system gauge never dropped below 15 VDC. In general, I kept the engine above 2000 rpm.
When I returned to the house I let the engine idle while I went inside to get the trickle charger (This was a guess - my 2A/10A/55A charger failed in 2016 and I have not replaced it. I would not expect driving the Xj for 50 minutes would provide me with much battery capacity.). I connected the trickle charger to the Xj battery cables at the terminals, plugged it in the 120 VAC outlet and shut the engine off.
In walking around the rear of the car I realized I was in the garage far enough to close the overhead so, I climbed in the Xj driver's seat and started the engine...no issues...easy start (for an Xj w/OEM single hole injectors!) just like all week. Moved the Xj forward a bit and shut the engine off. I disconnected the Xj battery cables and connected the trickle charger directly to the battery terminals. The initial response of the trickle charger was nothing (green LED). It has charging the battery for ~1 hour (RED LED).
Any ideas?
