getting car ready to ship to new owner,no charge light comes on, battery gage says low volts.

take V/M reading,,DARN, 11.9volts engine at 1200rpm.

OK guys where to look 1st and so on down the line???

WHY i love these cars is beyond me!

everything has been goin fine, and Bingo somethin else happens.

as somebody said ,,GRRRR.

1975 XJ12C

 

Does the Voltage keep dropping as it is running, or does it stay at the 11.9V ?

If it stays there. Just check the grounds, connections & terminals.

 

Is the alternator belt tight?

Loose wires/dirty connections at back of alternator?

If neither of those your alternator is probably on the blink

Cheers
DD

 

like said my alternator is not chargin,checked wires, all good solid conn.
question; why does Jag run two #10 wires from pos+ stud to back of alt.
or is it that just simple redundence.

someone on this site said they used a GM alt. anyone got an idea, around here all the shops double the price, when you say JAGUAR.

 

I did a little research, looked up your car at autopartswarehouse.com and rockauto.com. They offer reman alternators for your car. APW has it in the Autoline brand for $122, free shipping. Rock has it for $136 (AC Delco brand reman) after returning the core. That is a decent price range, you should avoid paying more than that.

You could also check with Ken@britishparts.com, they are a sponsor here I believe. David Boger has a used parts business everydayxj.com that might be able to help by supplying a used unit.

The alternator is listed as a Lucas 334-1537 66 Amp, you can do some further research and determine if the one you have looks like a Lucas by looking up some pictures online.

The two wires is just a simple method of achieving more capacity for high current flow. Instead of using a larger single cable, double up with two or more smaller ones. My Ford truck had a similar setup which I later converted to a single fatter cable.

I am not a parts expert, I just used the methods I normally follow for my own vehicles when researching a part. I hope it helps, and I apologize if any of the info turns out to be incorrect.

 

WELL! after much screwin around with this car, finally found the MAIN cause of ALL its electrical problems,(and why i got the car).

sometimes slow crankin, then clear up and spin fast?

all electrics have been replaced at different times, igniton amp,, coil,, plugs,, cap ,,rotor,, resistor pack, some relalys, some wiring
alternator,, starter motor,, 2 batteries,, bat.cables? and anything else jag shop could think of!!

BUT me, after meditating on problem, remembered the engine had been R&Rd back 3-4yrs, put a big amp meter across, engine to body gound,crank engine and HOORAY, over 100amps.
sounds simple to fix,new big #2 ground strap,right, yeah, after it burned up all the new components, like 3 ign. amps.ETC.

this PO had all kinds of money spent, in 3yrs, finally got rid of the car, totally discusted,(plus his wife said me or car)!

all because tech man,just threw new parts at it! never finding prob.
i guess you can blame jag engineering for putting ground strap out of sight, so it can slip past normal diagnoisis.

i now run an other strap from Neg. battery, body grd. to engine proper,all up top where it is VISIBLE.

THX to all who kept me thinking.

RON