For some strange reason over the past few days my car has been dying while idling in drive. The problem has not presented itself while idling in park or neutral.

In drive while idling it will occasionally shut off. While monitoring the battery gauge i noticed that the battery is losing charge for some reason while idling in drive. When in push the gas peddle the charge picks up and there is no issue. While driving at night with the head lights on the issue is much more apparent.

The battery begins to die while idling in drive and will shut off if extra gas is not given.

Can anyone give some possible direction on how i should begin to troubleshoot this.

My car is 1997 XJ6L

Thanks

Carthage

 

Carthage, it is sounding like to me that you alternator is starting to go. What I would tell you to do is to get a multimeter and connect it across the battery (set to the VDC setting). Now, start the car with all electrical stuff turned off, car in PARK. The multimeter should jump up to something around 13.7 to 14.4 VDC (may vary a little bit as Jag likes to put an initial charge on the battery right after starting the car and then bring it back down a little bit). Once the multimeter stabilizes out, if the voltage is under 13.5 VDC, then you need to have the alternator checked out. If they say the alternator is good, let me know, we will have to do some further looking. Before you run to the parts store to get parts, with the help of someone else, put the car into DRIVE (foot on the brake) and then see what the voltage is now. It should be the same as when the car was in PARK. If the voltage drops, another sign the alternator is on its way out. You can then test the alternator by turning on your headlights and rear defroster. Again, the voltage on the multimeter should remain constant. If at any time you see the voltage drop below 12.6 VDC, that is a sign that the alternator is not outputting enough current and you are sucking off the battery.

Hopefully this gives you a point to start with in figuring out your problem. Keep in mind that our cars are very sensitive to voltage variations. So, if the alternator is not playing nice, it can easily cause what you are seeing. Granted, a good inspection of the battery cables and a load test of the battery may not be a bad thing to do also.