The car suddenly started staling and the ABS warning light came on. The car finally stopped with a dead battery. I got a hot shot and things were fine unless I slowed down or stopped. I replaced the battery but now I have the engine light on. Is it the battery or the alternator.? Note, While I got a hot shot I read the voltage at 10.5 Volts at idle, but the battery was dead, so I think maybe it was a useless reading. Does the Jag have an idiot light if the alternator or/and regulator is not functioning?

 

check the charging voltage and amperage... at the battery .. the car has a battery light .. hot shot? is this a boost?

 

never heard of a Hot Shot either?
put a new battery in it
check charging system then
by chance is the color of the battery white?
if so possibly original battery

 

Hot Shot is a jump. This is not the original battery. The "battery light" does not come on. I assume that means it's not the alternator?

 

First thing you need to do is make sure you have a known good battery have you charged the battery you have yet? and then tested the battery to see if its good?
never assume anything with a jag
as a Factory Jag Technician trust me lol
this is from experience

 

words that are true.. lol
also check the power studs.. to the left of the battery.. the power nuts come loose and then melt.. causing intermittent voltage drope.. and also under the hood right side power post.. cable running from engine to under right side engine bay cover.. they melt and come loose..

 

Ok! I had it checked and one fellow said the charging system was good, and one said it was bad. So, to make things simple I determined it being bad because I hear a whining from the engine department. My guess is I lost a diode or and a regulator. Any comments?

Thanks

 

did you verify battery condition first?
is known good battery in car when you had charging system checked?

 

I replaced the battery with a new one. Again, the whining makes me think it might be a shorted Diode. But if you have other suggestions, I am open to them!

 

do you have a voltmeter?

 

Yes. Idle voltage, 12.25, 2,000 RPM 13.5

 

I must have missed the part there about the whining.
Remove the drive belt and see if noise goes away. If so, turn alternator pulley by hand. You can normally feel it clicking or binding up. If so, replace the alternator.
If the noise is still there with belt removed and engine running.....you have bigger things to worry about than the alternator.

 

I am back... Whining is still there, and it sounds a bit like it might be bleeding through the radio. The whining changes with engine speed. If not alternator what could it be?

 

Did you take off the belt and run the car for a minute to see if noise goes away?

 

Queston to FactoryJaguarTech
1993 XJS 6Cyl
Alternator smoked dash voltage drop to 9vts Replaced alternator dash voltage 13-14 vts. No charge on battery. Red battery light on dash. Suspect burnt brown wire between starter and battery....Am I on the right track?