AC System Question (1990 GMC Jimmy)

[HoytHarris]

Alright, so with the weather starting to get cooler where I am, I can't just suffice with the typical "All Windows Down" answer to my ac not working. The unit, from what I can tell, will work sometimes, but my question is to why it is just "sometimes". 90% of the time I am without AC/Heat, but occasionally, I will hit a big bump in the road, or a pothole that will kick the system on. It will then work perfectly and as long as the truck is running, but after turning the truck off and back on again, will not work. My question is why is this a problem and how do I fix it?

 

[frankin5]

Is the compressor cycling, do you have vacuum, electrical to the control panel. Is all linkage in good working order. Have you check the brake switch with the vacuum hose to make sure it is set right. If that switch is open the system will not work. Check for loose wire connections.

 

[Truckman4life]

My guess is if you are losing heat and a/c then your control panel has a crappy connection for the electrical or it is just wore out internally. When it goes out do you mean that the blower motor quits and you just get nothing?

 

[HoytHarris]

My guess is if you are losing heat and a/c then your control panel has a crappy connection for the electrical or it is just wore out internally. When it goes out do you mean that the blower motor quits and you just get nothing?

Yeah Im just getting nothing out of it. I haven't had a situation where its blowing and it just stops. When I crank the truck, it either blows, or it doesn't, the 2nd one being 95% of the time.

 

[frankin5]

Does all you accessories work all the time.