88 New Yorker climate control problem

[limeyj]

Just purchased an 88 New Yorker Landau, which has the Automatic Climate Control option. Problem is...the A/C conpressor clutch kicks in whenever the system is engaged, even when the A/C button is not pushed in manual mode. A sticker under the hood indicates the A/C system has been converted to R-134a, but it's low. What could cause this?

Also, in manual mode I can't switch from Defrost to Panel, to Floor, etc. It only blows from the defrost vents. I suspect the vacuum modulator for the diverter, but where is the durn thing? Under the dash with the diverter box? Or under the hood next to the firewall? (I noticed a vacuum modulator there with a line running through the firewall.)

Any help would be appreciated. Nebraska summers can be brutal! ; )

[special tool]

because it's been switched to 134a doesn't mean any thing and if it's low the compressor should cycle. I would think all the vacuum modulators should be under the dash? Sounds to me since you manually cannot switch it out of defrost the control itself maybe the problem. If you can switch it out of defrost and go to the dask outlets but it does not switch then I would say either a vacuum leak or the door motor itself. Good luck I know those Nebraska summers first hand!!!!!!!!!!