Perhaps someone on the forum could enlighten me. My 89 XJS has suddenly started drinking the battery. Affter it sets for a couple of weeks. If. I remove a terminal it's good to go when I hook it up so that tells me it's probably not the battery. Not being good at all with electricity how do I go about checking it. When you first start it I get a red battery on the dash for about 60 seconds then it goes away. I checked the belt all seems well there. Where do I start?

TIA

 

This is normal, the charging/lightning bolt will come on when the battery voltage is higher than the alternator voltage, ie when you turn the ignition on before you start the car.

Or if the alternator voltage is higher than the battery, indicating a possible faulty battery.

In your case the light goes out so the charging system is probably ok. You can check this with a Multi Meter. Charging voltage with the car running should be between 13.8 and 14.4 volts, this will depend on the state of charge of the battery.


To me this looks like parasitic drain, could be car alarm or boot light not going off.