Battery warning light
 

Hi all,
I have a 1987 XJ-6 (series iii) and it is showing the ignition warning light (red pictogram of a battery) when the car is on. According to the use manual, the light should only be on when starting the car and not when the car is in use. The battery voltage indicator is showing slightly lower than normal levels. Any ideas on what may be causing the light to come up and what I can do to rectify the problem?

Thanks

Hi Dollajaag,
The light goes on when your alternator is not charging up enough.
Not sure about slightly lower than normal, how far is it left of the 12?
Does it stay on all the time? does it go off when you're parked and rev the engine?
If the gauge does not go up or the light goes off when you hold the throttle down, you're likely looking at an alternator that needs to be rebuilt.
Do have the alternator tested first.
Over here in Toronto, rebuilding cost about $135 swapping your core if they have one on the shelf or takes about a day to turn around.
Cheers

First before spending anything, check your alternator drive belt tension and or wear.

If loose, tighten. If worn out replace.

Batt should be reading about 13.6 when running. IIRC

The light stays on, an even pulses under heavy acceleration. The lever is halfway between the 10 and the 12. I'll have the alternator tested, thanks for the advice.

Hi, I've just consulted with Fitzy the Jaguar Master Tech to confirm.
He said if the alternator is working properly it should be charging 14 - 14.5 volts and if you're showing between 10-12 it's draining the battery so be please be careful if you're still driving.
Swapping out the alternator is straightforward if you're doing it and very fast when done by a tech, you should also inspect & perhaps replace the belt while you're at it. It's only $10-$12 and you'll have peace of mind.
Cheers

all good advice given previously however just check the push on connections are tight and getting good contact on rear of alternator..........similar thing happened my series 3 and it turned out to be connections, worth checking first only takes a minute?