Hi everyone.
On the way home from dinner tonight with the AC in my '90 Majestic keeping us cool it crapped out.
That's it nothing - no dash fans, no air flow; nothing. The fuses all appear OK and I am inclined to think that it's either the AC ECU P/N JLM2212 or the control panel P/N DBC 5844. Any advice?
Thank you all,
Roger

 

First thing to check would be the micro switch on the control panel - $5 part from radio shack - good illustrated post in the archives on swapping it out.

Larry

 

Roger,

I just ran a search on ebay, no less than 18 DBC5844 were available, one was as low as $50 up to $200 for a never used (new) unit. I have two, one as a back-up in case the micro-switch Larry referenced decides to go.

If you get no response from the unit on any speed, replace the unit, if there is fan activity on the lower settings, replace the micro-switch. I have rarely, if ever, heard to the ECU being the problem....then again....it's a Jag.

Larry, correct me if I'm wrong, but I thought the micro-switch affected the variable fan speed settings. IIRC, the relays in the blower assemblies only know one setting, as in full power, and the micro-switch sent a variable voltage signal for the lower fan settings.

 

Thanks Rob, great minds think alike! I just bought the EBAY NOS unit for $84.00!

 

You're probably right Rob, I assumed the micro switch ran the panel controls and I thought I read that if the panel is dead (no lights) then the switch had failed.
Back when I started rebuilding the climate control and a/c systems on my '94, I replaced the micro switch only to find out later that the switch issue only affects earlier MY panels.

all the best

Larry

 

My problem was the micro switch in the control panel.
I bought a NOS control panel that was very reasonably
priced off Ebay and popped it in this PM.
I also bought the Jag micro switch kit P/N JLM11240 which I
will use to repair my original panel and I'll have a spare.

 

Here we go again...! So my wife takes the Majestic this AM and when she returns she says "the AC isn't working honey".
What says I! Leaky hose. Hose P/N CCC5504 (special order) is leaking at the crimped fitting at the expansion valve.
So...I ordered three new hoses and a new receiver dryer along with new O rings for the service fittings on the compressor.
How often do I advise everyone to not cheap it out and replace everything
25 year old hoses may look good and not leak initially, but they won't last!
I should have known better.