So my 98 Mark VIII has worked pretty much flawlessly for the past 8 years when all of the sudden my AC quits working. :mad: Clutch is not coming on to engage the compressor. Further, my cooling fan is not coming on either. I get no power to the plug on the fan when I have the AC turned on.:shifty:

HELP!!!

Thank you in advance.

I would check your maxi fuses, inside the power distribution box. Located inside the engine compartment. The fan and a/c clutch engagement are controlled by the VLCM, but if the car starts and runs its prolly not that.

Yeah it starts and runs ok. Fuses look good also.:confused:

Well, then remove the connector from the vlcm and see if you have power at the appropriate pins. If you do, then it's prolly the VLCM.

Edit: On second thought, does the fan come on after the engine reaches proper temperature. IF it does, you might have a bad a/c controller. Main pcm might not be getting a signal to turn on the a/c! Just another thought.

AHD,

Thanks for the input man. I appreciate it.

The fan does not come on at all. Regardless of the temperature.

I will look through my factory shop manuals, I promise. But a quick question.
What is the VCLM and what does it do? Laymans version please.

I have been working on my fastback for the last several years and the Mark VIII is my first foray into the late model performance scene. So I appreciate your patience.

Variable Load Control Module. IF you look thru the grille, a little to the drivers side you should see a small black box with fins. At least that is where it is on the Gen 1. It receives commands from the main pcm via a databus.

Edit: The vlcm controls the physical operations of the cooling fan, a/c clutch engagement, and fuel pump. It is commanded by the pcm.

I would check your maxi fuses, inside the power distribution box. Located inside the engine compartment. The fan and a/c clutch engagement are controlled by the VLCM, but if the car starts and runs its prolly not that.

When my cooling fan stopped running, it turned out to be a bad VLCM. Everything else still worked fine.