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Delanair MkIII - exterior ambient temperature sensor location

Posted: Sun Apr 25, 2021 6:30 pm
by AndyF
Hello all,

Can you tell me where I would find the exterior ambient temperature sensor (MHD6540AA) for the Delanair MkIII on a 1994 facelift V12?

As far as I can work out, there are 3 temperature sensors - the interior temperature sensor/aspirator in the knee roll on the passenger side, the evaporator temperature sensor (to prevent icing) and an external sensor... but where is it?

Many thanks

Andy

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Sun Apr 25, 2021 10:18 pm
by cafcpete
Pg 39 says it’s in the air plenum chamber in front of the windscreen.

http://www.jagrepair.com/images/Electri ... %20S83.pdf

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Mon Apr 26, 2021 2:11 pm
by AndyF
@cafcpete - thank you very much. I haven't seen that document before.

I am still investigating the overall performance of my air conditioning system - it is working well from a cooling side (in manual), the air blend flaps are moving to control air flow to the screen and close the footwell vents in full defrost mode but the cabin temperature is still a bit erratic in "auto".

I have cleaned out the cabin temperature sensor / aspirator in the passenger knee roll - via removing fluff etc with an air line etc and opened and remade the connections to try to ensure a good signal. So, my next angle of attack is on the exterior ambient temperature sensor and I will use the opportunity of taking the plenum apart for a good look round and clean out.

Any other suggestions gratefully received!

AF

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Mon Apr 26, 2021 2:54 pm
by AndyF
Found it, lurking under the wiper motor, on the LHS.
20210426_144533_resized.jpg
20210426_144533_resized.jpg
Looks similar to the illustration on the Jaguar Classic parts site.
External Temperature Sensor.jpg
External Temperature Sensor.jpg (11.26KiB)Viewed 1840 times
So, just need to get those wiper arms off and the plenum cover off... how hard can that be?!

AF

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Mon Apr 26, 2021 8:38 pm
by ng4xjs
Hi Andy - This is what I normally use to remover the wiper arms. I need to get in there myself shortly as I have, what I expect to be a slight blockage on my near-side washer nozzle.

Good luck.

Nick

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Tue Apr 27, 2021 9:55 am
by cafcpete
I don’t have this system so can not offer any advise, but these manuals may help.

https://www.jaguarforums.com/forum/atta ... uction.pdf

https://www.jaguarforums.com/forum/atta ... ontrol.pdf

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Tue Apr 27, 2021 11:53 am
by PaulGover
Hi Andy - This is what I normally use to remover the wiper arms. ...
Blimey! I've never needed more force than a light "waggle" of the arm. It's not a force-fit, nor is Loctite appropriate.

Re: Delanair MkIII - exterior ambient temperature sensor location

Posted: Tue Apr 27, 2021 6:31 pm
by ng4xjs
Sometimes it needs more than a wiggle if they' have not been off in a decade or two. If so something like I posted applies an even pressure which must be a good thing :)

Nick