Nothing related to the climate control seems to be working on our 08 XKR.


No fan in automatic or manual mode, no air (hot or cold) from any of the vents.


The blower motor fuse (F34)in the rear seat fuse compartment looked good.
Anything else I should check before I make the dreaded trip to the dealer?

 

Try replacing that.fuse with another one of the same size from that fuse panel that you know is good. Sometimes looks can be deceiving.

Does your A/C compressor click on and run? Any other fuses?

 

I only have an 07 electrical drawing (attached. P.27) but it looks like there is a relay in that same rear seat fuse box (aka Auxiliary Junction Box). It is R1. If fuse #34 is in fact good, I might buy one or try swapping out the relay with an identical one from another spot and see if my blower works then. (For example, If I was sure R3 is the exact same color/type of relay and my car was the car in the drawing, I would use that one since it looks like it feeds the rear window heater and the convertible top latch...I would just avoid operating those in any way for my experiment).

https://www.jaguarforums.com/forum/x...xk-how-121629/

 

Jacsun - thanks for the electrical diagrams.


I have voltage to both sides of the fuse - next is the motor. On the other side of the motor is the Control Unit Blower Motor Front which gets it signal from the Automatic Temp Control Module.


Anyone know where these control modules are located?

 

From my 07 repair manual:

The ATC (automatic temperature control) module is mounted on the end of the blower motor casing, behind the instrument panel. The ATC (automatic temperature control) module processes inputs from the TSD, the control switches located below the TSD, and the system sensors. In response to these inputs, the ATC (automatic temperature control) module outputs control signals to the A/C (air conditioning) system and the heating and ventilation system.

In addition to controlling the A/C (air conditioning) system and the heating and ventilation system, the ATC (automatic temperature control) module also controls the following:
• The seat heaters. For additional information, refer to Seats (501-10 Seating)
• The rear window heater. For additional information, refer to Glass, Frames andMechanisms (501-11 Glass, Frames and Mechanisms)
• The windshield heater. For additional information, refer to Glass, Frames and
Mechanisms (501-11 Glass, Frames and Mechanisms)
• The exterior mirror heaters. For additional information, refer to Rear View Mirrors (501-09
Rear View Mirrors)
• The steering wheel heater (if fitted). For additional information, refer to Steering Column
Switches (211-05 Steering Column Switches)
Two electrical connectors provide the interface between the ATC (automatic temperature control) module, and the vehicle wiring. The ATC (automatic temperature control) module uses hardwired inputs from the system sensors, the LIN (local interconnect network) bus to communicate with the stepper motors and the medium speed CAN (controller area network) bus to communicate with other control modules on the vehicle.

 

Here's a diagram

 

Another thought just crossed my mind. I had the vehicle at the dealer for maintenance in May and they replaced the cabin filter. Could there be something they did or didn't do that could be related?

 

Maybe this is better

 

I guess anything is possible but changing the cabin air filter was a very simple under-the-hood process which requires no touching of anything electrical.

Admittedly I am not the best electrical person but since you had the tools to check voltage at the fuse you might want to try looking up under the passenger footwell and disconnecting the plug to the blower motor. There may be a thin "decorative" panel you have to remove to access the parts under there. The blower motor is pretty obvious with the wires going into it and 3 mounting screws. With the plug disconnected turn on the climate control and fan and see if you are getting voltage across the two leads that plug into the blower motor. I just did it on mine and with the car not running got 12.25v with fan on full and 10.15V with fan on first setting (but disconnected from the blower motor). If you have voltage I think the control unit is fine and you are left with a dead (open) blower motor.

 

Just thought I would update this tread.
In troubleshooting the problem, I found I had 13.5 volts at the motor, so that eliminated the fuse and relay. I then bench tested the motor which worked fine.
That left the most likely problem being the Blower Motor Control Module. I went ahead and ordered the part (Airtex WMA 4P1652) from RockAuto. Total price including shipping a little over $80. Easy to install - just drop the panel under the dash on the passenger side (3 clips) and remove the 2 screws holding the module located just behind the courtesy light. (note: the light is hot, best to remove it from the holder and get it out of the way).

 

And?............... (i.e. did that resolve the issue?)

 

The issue is resolved! Thanks to all who contributed to this thread.