Hi guys i am working on a 1990 dodge truck 5.9 diesel and the ac compressor wont engage unless you short the connector it will run wondering if maybe the freon is a little low and what are the pressures supposed to be and the power windows wont work either fuses are fine any help would be great thank you

 

The pressure is "variable" depending on the temp, humidity, etc.

Do you have a set of manifold gauges? You also need to determine if you have any freon in the system or if you have a leak.

For your power windows see if you have power to the switch.

 

did you test to see if there is power at the fuses? to me it sounds like your fusible link is blown. you may want to look at the orange fusible link that is connected to the pink wire on the drivers side fender.

 

what color of wire is the power wire to the power window switch the truck is a 1990 dodge 3/4 ton 2wd

 

have you looked at the fusible links?

 

Hi again i got the power window to work on the drivers side but it is really
sluggish and needs help going down and up i am assuming its the
window regulator that needs replacing if its sluggish like this
the passenger side window doesnt work but has power to the switch
so i guess i need a new switch for the passenger side and the ac problem
i installed a set of manifold gauges on and bypassed the pressure switch
and the low side pressure is 0 psi and high side is 50 psi i am thinking the
compressor is faulty if any can help that would be great

 

i tried putting in some freon with the compressor on and the pressures never went up