met a guy at the junkyard last weekend who told me that the jag alternator could be replaced with a GM unit. Just have to measure the width and find an exact fit. Works perfectly, no issues according to him. His son also said something about replacing the plugs with direct ignition coils. Not sure about that one. Anyone heard of this?

 

Brad, an alternator is an alternator, any that will fit will do the job. My belief, after years of my car eating alternators, is that the OEM 75 amp job is just not up to the demands the car makes. Once, on Grant Francis' advice I fitted a Jaguar 115 amp alternator, all my troubles disappeared.
As for coil on plug ignition, in my opinion on the Lucas V12 it would provide no real-world benefits at all; other than giving you a headache getting them into the V. It would also entail fitting an entirely new aftermarket fuelling and ignition system which would be needed to drive them. And FWIW, my experience with ANY aftermarket electronics I have ever fitted to my car is that they fail in very short order.

 

I would steer clear of COP (coil on plug) a lot of the new cars that run these have issues with them failing. A mate of mine with a BMW 545 keeps a spare in the boot so he doesn't get stranded again.

 

Whew, down to 9 volts!!! I've had a few go quite low, but not that far, I don't think!!!


The last event was on my Jeep. My daughter borrowed it whilst I sought to fix her stumbling VW v6 powered Passat.


Alas, my elderly high mileage, but hereto fore reliable Jeep conked out on her. Not too far from here. So, after some road service misadventure, They got here on a flat bed.


Next day I began the diagnostics.
1. Flat battery, no crank. Ugh, "daughter, if it dowen'rt crank up in a few, it ain't going to, fix time".


Schumacher "smart charger" not effective??? Removed cables and placed charger's
direct to the posts. Schumacher responded. Long and slow and battery at 100%!!!


Lesson: Cleaned posts and cables and replaced the cables to the posts.


1st result: Jeep cranks fine but does not fire.


2nd result. Another story told elsewhere.


Carl

 

Check the signal wire for corrosion or continuity. If it is not sending +12v from the ignition the alternator is not going to charge the battery.

 

I agree. Replace the alternator with a higher amp unit that fits and many problems will be resolved. I also agree that fiddling around with after market modifications like coil in plugs is asking for trouble. The car was not designed for it and any after the fact efforts are likely to lead to trouble.

 

Coils? I have enough trouble with oem parts!