Note: 3 STEP CHARGING SYSTEM. Do a search here if you don't understand how that works. If it does not step charge properly, it will throw codes.

 

Hi Thermo I am having a similar issue to this fella and I have a 2002 Jaguar X-Type that has no power coming from the alternator and I ran over occur with little passenger side tires per hour and then slowly lost all power exactly as stated and I'm currently with a charge battery able to run the vehicle and it slowly dies with all systems not operating properly and the alternator is cranking out 0% using a shumacher alternator battery charger tester is this the same as his problem I'm assuming and thinking that it is if so should I do the same with testing the voltage
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QUOTE=Thermo;379524]Ernest, ok, this should be fairly simple. It sounds like you have access to the alternator, so, this is what I want you to do: If you look on the alternator, you will see a large wire coming off of the back of the alternator and then a 4 wire plug on the side of the alternator. First, measure the voltage at the large single post with the motor running and write the voltage down. Next, locate the green wire with a red stripe (don't confuse it with the red wire and a green stripe). Measure the voltage there and write that down. Finally measure the orange/green wire and write that voltage down.

Ok, now for figuring out what is wrong with your car. If the large single wire is up at 13.7 VDC or higher, you have a bad wire between the alternator and the starter (you don't mention any problems with getting the motor started). If the voltage on the large single wire is under 13.0 VDC and the green wire with a red stripe is reading under 12.0 VDC, you have either a bad fuse (Fuse F6, a 7.5 amp fuse in the engine bay fuse box) or the green/red wire has a problem and a new wire needs to be run. If the green wire with a red stripe is up above 12.0 VDC but the red wire with a green stripe is under 11.0 VDC, you have a problem with the GEM or the wire between the alternator and the GEM. If the green wire wtih a red stripe is above 12.0 VDC and the red wire with a green stripe is above 12.0 VDC, then your alternator is toast and you need a new alternator.

Hope this helps and if you need any more info, let me know. Please keep in mind that this assumes you have a car made after March 2004. If you have one made before then, let me know as the fuse number is slightly different (Jag made a design change to the car and renumbered things).[/QUOTE]

 

Ngrb93, yes, do the same tests. I want to say that the charging systems of the X-Type never changed through the history of the car. So, that should be good info. The only bit that may have changed is the fuse number (that changed in MY 2004.25). But, this is all good info to help you narrow down where the problem lies. But, I would be looking at either the battery cables or the cable running from the alternator to the starter. You get some corrosion on any of these connections and you can see what you are seeing. The alternators in the X-Types are pretty bullet-proof and rarely have I seen one fail. Tons of wire issues though.