Delanair MK IV HVAC system FAQ

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Mar 10, 2014 | 08:45 PM

JimC64

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Joined: Nov 2006

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From: Glasgow, Scotland UK

Delanair MK IV HVAC system FAQ

Please see details below, as kindly supplied by Rob Evenson

https://www.mediafire.com/?b7pwpvotajvifvg

Mar 11, 2014 | 08:14 AM

Rob Evenson

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Joined: May 2012

Posts: 492

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From: Mobile, AL USA

Document explains the HVAC system for the 88-94 XJ40

Jim,

Thanks for uploading the document to the forum.

I can't take credit for the document. I can't remember which site I found it on, but it is very helpful in visually understanding how the AC/Heater system works in the XJ40.

It details the CCU, the upper/lower flap mechanisms, the vacuum actuators/solenoids and vacumm tubing lines for the center dash air box and how the flaps are affected.

It also explains how the blending of cool and hot air is accomplished and what position the blending flaps should be in when the user set the control unit.

It is a must read for anyone trouble shooting the system.

Hope it helps many XJ40 owners.