ok im doing the a/c on a 84 s 12a. we have vac. it down and refilled it with 134. if i hot wire the clutch is bolws nice cold air. but it wont do it on its own. i have swaped out the relay and have hot wired/ bypassed the 2 safty switchs and still it wont do it on its own. every thing looks right, a/c light works fuses are good but i cant figure it out. any help? ideas?

 

Sounds like it still doesn't have enough R134 in the system. That is usually a symptom, so it won't burn itself out.

But, I really don't know...That's just from past experiences.

 

well heres what we did... slaped the guages on it yesterday (when we filled it) about 70-75 deg. out side and we had 30 pounds on the suction side and 175 on the discharge side does this sound right? what SUPER cold when i hot wire the clutch. also i dont see ANYTHING moving in the receiver dryer.. most of the time you see bubbles.

 

30 inches you mean, and you should see a milky froth moving past the sight glass when it's on. The pressures seem fine, do you know the head temp? How about the output temp? How did you bypass the pressure and temp switches? You did pull a vacuum before you filled the system, right?

 

the #'s were PSI 30 psi on the suction side,175 psi on the discharge side and the out side temp was 70-75 f. nope didnt have a temp on the head or the output(vent) yes we pulled a 26 psi vacume it held for 2 hours so i figured it was good enuff. the switchs i just unpluged and x the wires, hell it worked fine with the switchs hooked up but i had to still jump the clutch. so what could this be ? why wont it work? anybody got a chart showing what psi @ set temps i should have oh and this is 134 if i didnt say so before