My 95 XJS developed a problem and I can't determine if it's the battery or the charging system.I am requesting some suggestions and have listed a few things that might shed some light.
1) 51,000 miles (I'm the original owner)
2) Battery has run down as I don't drive it much, and has gone to completely dead a few times - yes, I know that's on me. (I now have a smart charger)
3) I put a full charge in the battery, reconnected it and the "BAT" light shows.
4) As soon as started, the dashboard charging gauge goes to 9.5 to 11.0 and slowly drops as the car is running.
The problem started after the battery went completely dead.
The battery might be at 12 volts, but could the amperage be affecting it?
Thank you all.

FC

 

Frank,

You need to establish a few more things. After you have fully charged the battery and fitted it in the car:

- Measure the voltage at the battery terminals Needs to be 12.5v+. If not, then the battery / charger is suspect.
- If over 12.5v at the battery terminals, now measure again at the bulkhead terminals. If not within 0.1v of the voltage measured at the battery terminals, then you have a wiring / earth point problem.
- If battery voltage acceptable at the bulkhead terminals, then start the car. Wait a few seconds and also blip the throttle to ensure the alternator is operating.
- Now measure voltage at the battery terminals. Should be 14v+. If not, then likely that alternator / regulator or fan belt is suspect.

Cheers

Paul