RADustin
Full Access Member
- Joined
- Mar 27, 2017
- Posts
- 111
- Reaction score
- 8
- Location
- New Orleans
- First Name
- Dustin
- Truck Year
- 1976
- Truck Model
- C20 Crewcab
- Engine Size
- 454
Gents,
General question I know, but I want to try and fix the AC in my '76 as I think it will help the sale. Don't worry, I am replacing the truck with another square.
Anyways- The heater works, and for the MOST part the blower motor does want I want as far as changing speeds. But it doesn't all the time. Sometimes it doesn't come on at all. Do the dash switches go out? or are they serviceable? I heard of a relay that goes out often, any ideas where this is and what it controls?
I don't think it's really switching modes either, from heater to AC. From what I recall, the heater works when it catches but it doesn't switch over every time. The blower motor is kind of intermittent as well.
Does anyone have an electrical diagram of the system so that I can first check that the controls are working? Also, maybe an overal functional diagram of the system so I know what is electrical and what is mechanical. I'm imagining the heater valve is mechanical. From there I will check refrigerant charge and pressures. I think I can get a handle on everything once I am sure the dash controls are correct.
There has to be some sort of electrical gremlin because while adjusting the modes the [factory] tach will jump. So I'm wondering if there is some sort of ground loop or similar causings issues. Anyone else ever seen this?
I appreciate any help. TIA!
General question I know, but I want to try and fix the AC in my '76 as I think it will help the sale. Don't worry, I am replacing the truck with another square.
Anyways- The heater works, and for the MOST part the blower motor does want I want as far as changing speeds. But it doesn't all the time. Sometimes it doesn't come on at all. Do the dash switches go out? or are they serviceable? I heard of a relay that goes out often, any ideas where this is and what it controls?
I don't think it's really switching modes either, from heater to AC. From what I recall, the heater works when it catches but it doesn't switch over every time. The blower motor is kind of intermittent as well.
Does anyone have an electrical diagram of the system so that I can first check that the controls are working? Also, maybe an overal functional diagram of the system so I know what is electrical and what is mechanical. I'm imagining the heater valve is mechanical. From there I will check refrigerant charge and pressures. I think I can get a handle on everything once I am sure the dash controls are correct.
There has to be some sort of electrical gremlin because while adjusting the modes the [factory] tach will jump. So I'm wondering if there is some sort of ground loop or similar causings issues. Anyone else ever seen this?
I appreciate any help. TIA!