Hey y’all, ian here, with a somewhat emergency question, recently I went out for milk in my xjs, and she stalled on my way back home and needed a jump but that jump didn’t get me far, and I had to get her towed home. Also the store was out of milk anyways. While waiting for a tow I tried to start the car and got the evil clicking of low battery. I belive I’ve come to the conclusion that the battery isn’t getting charge from the engine due to the alternator. I really hope I’m right here, and this probably explains why I’ve gone through 4 batteries in the past year and a half.
The reason this is an emergency is on Wednesday I have senior portraits and we want to use the car in the photos. Today is Sunday. Under normal circumstances with your Normal car you can google what you need or even go through this forum but I don’t currently have time to research today and I have school this week so I wanna save my spare time after school Monday and Tuesday getting the part and installing it.
So, my question is a multi parter:
*where do I remove/ install the alternator?
*is it a special part or is it normal?
*is it as complicated as everything else to do in an xjs?
*do you think this is doable in 3 hours a day over two days in my back yard?
Everyone who helps out here will be heavily thanked and praised by me for quick help. I know I sound crazy but senior portraits are $1,100 and i rarely ever spend that much money, I don’t want to waste it.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
2
If the car will run at all, checking the alternator is easy with a VOM – and you can get a VOM for a song at Harbor Freight Tools. Simply put the VOM in DC volts mode and measure the voltage anywhere in the car, even in the cigar lighter. Rev the engine to 1500 rpm or so. The voltage should be between 13.6V and 14.4V. If it’s either lower or higher, the alternator is suspect.
In the 1988-on XJ-S V12, it might not be the alternator. Those cars are notorious for crank damper failures, and the alternator is driven off the crank damper. But if the crank damper is OK, it’s a relative certainty that the alternator itself needs replacing.
I’ll be sure to look into that, and where is the crank damper located? Sounds like something I should know but I can’t think of it
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
4
Front end of the crankshaft. It’s what the front pulley is bolted to. It’s got an iron hub, an iron outer ring, and the two are bound together with a ring of rubber. The rubber breaks loose, allowing the iron outer ring to drift around. Since that iron outer ring includes the grooves for the belt that drives the alt, the damper slipping means the alt isn’t being driven as it should. It turns, just not as fast as intended, so the battery never gets fully charged.
Easy to check. Using a marker of some sort, put a line on the inner iron ring and the outer iron ring that line up. Take the car for a drive, then recheck those marks. If they no longer line up, it’s time for a new damper.
Just remove battery cover and shovel spare battery into the trunk. That will always allow corpse reanimation for upocoming session.
One thing to mention - there is a gauge showing current voltage in the system. It is easy to notice if it’s below 12v… and when (should indicate approx 2/3 of the scale)
Simple drive belt tension would be the thing to check prior to Kirbert’s suggestion.
Ian…You make me remember when I WAS your age and into Jags! My friends were into Chevy/Ford, etc! I was 17 at the time!
I would charge the battery and see if the car runs ok. That would eliminate anything else like the alternator! If it ran ok, it would likely get you to school for your pics! You could then do the repair later without stress!
Indeed.
I can attest that with no lights or other auxiliaries on and a fully charged battery the car can do minimum 60km before it runs out of juice.
And a back-up battery on the trunk would add reassurance.
Unless specially designed as deep cycle batteries, lead acid cells do not like being constantly discharged to flat. That is what was killing your previous batteries. If you still have them, there are a few ways to get some further use out of them - have a look on YouTube. You may be able to resurrect a couple of them for emergency backup use. As to the fix, it is most likely one of - poor connections, loose belt, shonky damper, or broken alternator. The first two are easy to check and fix (get yourself a multi-meter, it can be cheap-as-chips for automotive use), Kirbert has given you the instructions on diagnosing the third, otherwise search the forums for threads on replacement alternators. There are non-Jaguar alternatives that are readily available, and won’t break the bank.
Mostly from top; the belt adjustment is from bottom. Remove right side air cleaner for room, remove the air pump (both from top); disconnect battery. The rest is like any other car.
Agreed. Anything along the firewall is a pain. I personally like dash work, so the evaporator and blowers don’t bother me- the expansion valve and firewall side would.
