The car is a 93 XJ6 with 80k miles. It was parked a year and a half ago. The charging system was fine then. I have charged up the battery and the car fired right up. However, the battery light indicator on the dash lit up and has remained on. I find it odd that the alternator would die as a result of the car sitting so long. The dash voltmeter reads 11.5 and drops as the car idles for several minutes. I am going to replace the brush holder on the alternator in hopes that solves the problem. I will then move on to the regulator on the alternator. Any thoughts are welcome. I will keep updating as progress is made in hopes that someone else may benefit from this issue. Thanks for reading my post.

 

I assume then that the alternator is not actually charging and that the dash meter is accurate. maybe the brushes are just stuck .Also, if it sat unattended for a year and a half I think I would apply equal suspicion to the battery. I had a battery with one bad cell. The car would Usually start, and it made the electrics act funny, but it always tested good.
Good luck!

 

New brushes and a new regulator were installed. The alternator/battery light did not shut off right away but did so after I let the car sit and I charged the battery for 2 hours. However, now when I rev the car to 4000rpm I get sparks emitting from the alternator housing. Furthermore a leak in the hose from the thermostat leading to the waterpump has shown itself. This hose is above the alternator by the way.

 

Hi supra-raleigh,

See my replies and questions to the sparking and hose questions in your other posts.

Regarding the battery charging issue, have you had the battery tested under load, especially while cranking the engine? Jag saloons require a strong, healthy battery more than any other type of vehicle we have owned, and the quiescent current drains seem to wear batteries out, especially in cars that are not driven every day.

Don

 

The Autozone battery tested good at Autozone even during their load test according to Autozone. The warranty on the battery lasts two more weeks. So, where should I take the battery for a more comprehensive test?

 

O'Reilly Auto Parts. Tell them you want the "big machine" test, not the portable unit. I ran in circles between AutoZone and Advanced (7 different stores) and they all tested okay. Took it to O'reilly and had the deep charge and deep individual cell test and the battery was bad. If you don't have an O'reilly, take it to a professional battery distributor for testing.

 

I removed the alternator again while I was installing some new coolant hoses. I took it to get tested and it failed - only 10V or so. I had an alternator specialist go through it, new bearings, new rectifier and the shaft was resurfaced. They even cleaned it up and painted it. Upon installation, the voltmeter now reads over 14V as it should and no more sparks. The climate control along with the blowers work as they should along with the radio!!!!!! The gear shift interlock is still an issue however.

 

Considering that I have had many denso alternators on many of my cars that lasted much longer than the one on the Jag, I presume that the coolant leak that I addressed earlier on the car (in Dec 2012), the water rail hose under the manifold and right above the alternator, caused the alternator to fail at 80k miles. So, I recommend using a plastic bag to cover your alternator when working on the cooling system hoses/parts in the area of the alternator. Hope this helps someone. Thanks gents.