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Air temp actuator/HVAC controller problem

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I wish the solution was so easy for me. I replaced the solar sensors because the Tech 2 was showing that they were not changing with light/dark input as they should. The new ones (AC Delco OE) are exactly the same!

I also reset the IPM and did a HVAC recalc in the DIM (this is suggested in a TSB for HVAC not settling on a temperature. Not my problem but thought I'd try it).

I don't know what else to do. The fact that the actuator responded to the first used replacement HVAC control module (until I unplugged it. Plugging back in again, it no longer worked) makes me think it might be a poor connection at the HVAC control module conector. I have had a close look at the harness (looks fine, no obvious damage or poor connections) and have plugged and unplugged three different HVAC controllers many times now without any change. 

The only thing left is to replace the DIM. Unless anyone has a better idea. I hate the fact that I am swapping out parts to fix this and none are working.

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  • 3 weeks later...

Found the problem. There are left and right air door actuators. I had the right door when I should have had the left.

The reason? On the parts guide page you find on gmpartsgiant, it offers 'driver' and 'passenger' side actuators, and then says for RHD export, then regular KS, KY models. So I read that simply as 'passenger side, RHD models'. 

What it meant was passenger side, regular LHD models, but also for RHD. But not RHD passenger. LHD passenger. So RHD driver's side. A bit confusing isn't it? A confusion that cost me hundreds of dollars to figure out!

It took an auto electrician 3 hours to discover the fault and he just reversed the polarity of the actuator door movement, a three-pin plug within the actuator. That fixed it, it now responds perfectly.



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Glad your stuck with it and solved the problem!!  Good for you!!  Sorry it was so costly and time consuming to solve.  This is a great thread for RHD exports

Interesting that is did involve the RHD configuration, that sounded like a mess to sort out.  

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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