Try this

 

MY 2003 v. MY 2001 difference:
------------------------------

The 2001 Electrical Guide that Jack posted above (post #41) shows a major difference from 2003 in the routing of the alternator wire (yellow) which is used to determine whether the battery is being charged.

For MY 2001, the wire goes not to the ECM as it does for MY 2003, but rather to the Major Instrument Pack, connector FC26, pin 22.

This connector is below the fuel/temperature gauge.

Noterman is on board with this difference.

 

Today I pulled the dash apart and found the Major Instrument Pack circuit board and plug behind the gas/temp gauge. I found the plug to be secure and all pins clean and straight. The plug was also clean.
I figure I now have two options. One-tape over the message center. Two- park the Jag in downtown Minneapolis with the key in it.

 

FOUND THE PROBLEM. Thanks to Dennis 07, we traced the wiring from the alternator to the dash. I could not get continuity on the wire. I pulled apart the junction box on the firewall, under the throttle body and found one bent pin. I straightened out the pin and that fixed it. When I changed the engine I must have bent the pin.
Thanks to everyone that helped me with this. John

 

Cool! I'm glad it was something simple. I figured it had to be something with those wires from that plug to wherever they went.



Dave

 

Noterman deserves an award for tenacity. Well done!

Credit is due to WhiteXKR for providing a key insight: that the voltage gauge needle and not-charging warning light are completely separate circuits.

 

Nice work guys...glad it is resolved !!

 

My 98 XK8 - today for the 1st time got a battery not charging msg on the dash and the dash dial dipping to the left, got me home ok, i've not done anything to the car to cause this.
Earlier this week i was getting a failed rear bulb msg on the dash - and now this, i haven't had time to change bulb (which one?)
The failed bulb is one of the o/s rear - when you brake and indicate the all the red lights on that cluster blink weakly as well as the indicator/blinker.
Short? Fuse? any thoughts?
I can't be the same problem as earlier on this thread - i've only drove the car - nothing mechanical or electrical has been touched.
Hoping for a quick fix

 

Sorry to wake an old thread, hope you have email notifications enabled but I have the same exact issue. Notherman where was the junction box on the firewall? Is it the big black one with 1" dia sleeving coming out of it?

Cheers.

 

Noterman had done an engine swap, and the connector pin got damaged in the process of opening and reseating connectors. It you haven't opened any connectors it's very unlikely you'd have a problem like this.

Post 41 above links to the MY 2001 electrical guide. The version of the guide for your MY (Google should find it) should give you what you need to trace the signal (or lack of it) from the alternator to the voltage gauge.

Good luck.

 

Thanks Dennis good point. I have the 1997 diags but I have a Nov 1996 model and can't find a multi-connector stated.