XK8 Auxiliary Heater pump - wiring diagram

[terry.263]

My 2000 convertible is blowing fuse no 3 which I believe controls the auxiliary heater pump (and I guess other things). I have replaced the pump with a refurbed unit and the heater works briefly - until the fuse blows again !
Any ideas or where can I find a wiring diagram ? Cheers, Terry

[aaj]

Terry

I have Wiring Diagrams for a number of X100 Model Years

Although the Wiring Diagrams for the Climate Control System look the same for MY1999 - MY2001 (your 2000 Registered XK8 could be any of these Model Years) it is possible that there are subtle changes that don't immediately stand out. Please PM me the last 6 characters of your VIN & I'll send you the appropriate Wiring Diagram

Regards
AllanJ

[Astromorg]

Fuse 3 in the engine compartment fuse box does not protect the heater pump directly; it protects only the operating coil of the relay that switches that pump on. Your heater pump itself cannot be the problem, though the relay could be at fault.

Just as likely is one of the other circuits protected by that fuse. They are the fog lights relay coil, the headlight self levelling system (if fitted) and the adaptive speed control system(if fitted)

But there's one more circuit that does have a bad record for blowing this fuse that can be difficult to identify as it's shown only on the diagram of the security system and that is not included in the published electrical diagrams for the 4.0 models, so can be overlooked. However, by interpolating from the 4.2 model drawings that do include the security circuitry, it's clear that the rechargeable battery powered security sounder is also fed from Fuse 3.

(I think) in all X100 models the sounder is in the driver's side front wheel arch. If this system is the cause of your problem, simply disconnecting it will solve your immediate problem, then check out this link that might help you decide which way to go

viewtopic.php?f=63&t=16008

But it still might just be a faulty heater pump relay coil

[andypryce]

Correct, it is in drivers side wheel arch, easily accessible by removing the wheel arch liner and simple plug to remove. Doing so does not affect the main alarm in any way.

[JimMann]

The February 2022 Modern XK column will have a full piece on the secondary sounder and replacing the batteries that are the cause of a couple of issues once they stop being rechargeable. So if your investigations do lead you as Astromorg directs, a fix is to hand. If you need an early copy of the access and repair process, drop me an email, address you will find in the magazine at the top of the Modern XK Section.
Jim Mann

[terry.263]

Brilliant - thanks for all the replies, I am amazed how fast help is coming in !
The last 6 characters of the VIN on this car are A09118
If AllanJ could let me have a suitable wiring diagram that would be very helpful and then I can pursue the options outlined !
Cheers, Terry

[aaj]

Terry
I've sent you a PM - re sending you a copy of the Electrical Guide
The Jaguar X100 series (XK8/R) MY2000 commences with VIN A00016 in April 1999 and ended with A11051 in July 2000
The Silverstone Special Editions commenced with A06139 and started to be made in February 2000 so your XK would have been made some time after that.
Regards
AllanJ

[terry.263]

Thanks Allan - have sent.
Cheers, Terry