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Hevac Unit


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Sorry Tom I didn't quite get that could you speak a little louder!!

Only joking but if you type in capitals this is taken to be shouting so please use upper and lower case or all lower case to avoid the potential for offending others.

As for the problem I would guess that your is a P38 sorry I cannot help I am still driving Classic Range Rovers

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is it LHD or RHD?

Does the book symbol come on almost immediately when you start the car?

Initial presumption is that the blend motors have gone. These are 3 motors which control the temp of the air on each side and also the distribution of the air in the cabin.

The commonly wear out as the HEVAC controller makes the motors over work in my opinion ( they react too quickly to slight temp changes ans so move back and forward a lot ). I reckon they would be a lot more reliable if LR built in a 5 to 10 second delay on them reacting to a temp change.

You can diagnose the full system by reading this page and the diagnosis section:


to change the blend motors, a good place to read up about it is starting from the link above and also:


Dont skimp on the blend motors. Some people say that you can get Peugot alternatives and splice the cables into the old loom. Personally, your better off just getting the complete loom for £200, and that way you have 3 complete new motors, all pre-wired.

If you do go through the route of changing the motors, then I highly recommend / urge you to change the heater matrix o-rings at the same time. The o-rings are rubber seals at the side of the heater matrix on the inside behind the dash. the rubber perishes and you are likely to distrub the seal when doing the blend motor. So replacement at the same time is a very worthwhile job for the sake of a few pence for the parts.

You can see more about the blend motors here:


This is a job you can do yourself if you want to. I have done it twice now on 2 P38's.

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