2010 Navigator/Expedition A/C issue

[Ed G]

Hi, I'm new to the forum and looking for help with an A/C issue on my girls truck.

2010 Navigator with dual climate control.

Its weird, but here goes.

Under 80 degrees ambient temp A/C work fine, at 81 degrees (according to outside temp display) the system begins to cycle between blowing warm and cold air.

She took it to a shade tree mechanic last year, he didn't really know how repair the issue properly, but he did something that had the A/C run full cold all the time, he told her not to touch the temp controls and it worked all summer, went through winter and obviously used heat, now the same symptoms from A/C.

I've researched a bit and the only thing I've come up with is possibly reducing the shim thickness for the compressor clutch, but that doesn't make sense to me as it worked with whatever "fix" this shade tree guy used.

I spent about 10 years as a line tech at Lexus, I'm no A/C expert but I've fixed my share of all kinds of automotive issues, A/C included and this has me shaking my head.

Anyone have any insight or experience fixing issue on a Ford or Lincoln product?

Thanks

 

[stamp11127]

The air gap on the compressor clutch isn't what causes a system to cycle. If you want it to work correctly it should be put back to oem specs then troubleshoot any issues.

Usual causes of a compressor to cycle are the low side pressure drops too low or the high side pressures get too high opening the respective safety switch. On the fancier systems the control module can also cycle the compressor in normal operation.

A set of good gauges will tell you what is going on with the system pressures while running.

 

[Ed G]

I realize after rereading this I failed to mention something important......

The fan stops blowing, it doesn't actually blow warm air, its stops blowing cold air or any air. Also in the last two days there's a racket behind the radio sounds like a blind door motor skipping or something, very weird.

Thoughts?

 

[stamp11127]

Inspect the blower control module and the EATC module for any modifications the shade tree mechanic may have done. That way you know what you are dealing with. I would return the system wiring back to oem specs and repair any failure from that point.