Classic/Antique Car Repair: Jaguar-XJ6, jaguar xj6, jags

Question
Unable to maintain charge on 90 Jag xj6---have replaced battery, alternator,
and fuel pump. It will go for about 4 days without starting--then lose all
power. They replaced the battery again saying a dead cell---still died on me.
Help!!! What else can I have checked? What else could it be?

Answer
Hi Sharon,
I don't have any experience on any of the Jags after 1987 but a charging system should be a staright forward system like most others.
You need to check for a draw on the battery with everything turned off first. Then have a "Load test" done on the battery itself. If all of that is OK check the charge rate (13.8 to 14.5) Some driving conditions will run a battery down even if everything is OK, like getting stuck in slow trafic at night when it is raining and cool with the heater or defroster on.
If you don't have the equipment to do these tests, be sure your shop does them. Also check to see if you have the code to reconnect your radio or use a small jumper battery to keep it active. One other point is that Jags need "Deep charged batteries" like diesels do. If you install a convential battery in a Jag it will give you such problems.
Sorry that I can not be more specific. I hope this helps
HMF