1977 C10 AC not working, solution suggestions

[Steppin Razor]

Hi all. I've got a 77 C10 350 with factory air that has a leak. I generally am a warm weather person, but with summers getting hotter every year I want to get it addressed before my pup bursts into flames on the way to the park. I took it to a shop and the guy said the compressor is bad. There was a language barrier, so I couldn't get much more info than that. I can't do a $2200 vintage air complete kit to convert to R134. Youtube videos seem to suggest swapping to schrader valves and a new orifice tube is all you need to do to change over, but I'm not convinced that's the whole story.

So, it looks from the sticky above I can upgrade the blower with a unit from an '87. Do I just replace the compressor and recharge, or try to convert? The guy gave me a go away price to do it, and swapping the compressor looks pretty straightforward, so I might just get a Sanden (which one?) and swap it out myself, then get it recharged. Only thing is I'm unsure if he purged the system.

He also pointed out an electrical connection that was jumpered, I'll get a picture of that and post because I'm not sure what he was trying to tell me. Thanks in advance

 

[Rickf]

I took the most economical (cheapest) route and replaced the two pressure sensors, took everything apart, flushed everything, changed o-rings, added pag oil and charged it with 134a. It pumps out 40 to 45* air, I'd like to get it a little cooler incase I want to store dairy products.

 

[fast 99]

There should be conversion kits for that vehicle. Would have o rings, orfice tube, oil, and possibly cycling switch. It really isn't that hard. Swap out the o rings, flush out the R12 oil, change drier, add proper amount of oil, install charge fittings. Just be sure not to cross thread anything and lube o rings. Refill with 134 to 80% of R12 capacity.

 

[gmbellew]

the cycling switch is adjustable, at least on the later years (mine is a 1990 burb). so you don't need a new switch, maybe?

 

[Steppin Razor]

This is the jumpered connection.

I've never messed with an AC system before, so parts/terms/etc. are new to me, and I don't have the vacuum pump or gauges for doing the whole job myself. The drier is the aluminum can in the last picture, correct?

 

[HotWheelsBurban]

This is the jumpered connection.

I've never messed with an AC system before, so parts/terms/etc. are new to me, and I don't have the vacuum pump or gauges for doing the whole job myself. The drier is the aluminum can in the last picture, correct?

Yes, that's the drier(or some call it the receiver dryer).

 

[Steppin Razor]

Anyone know what the electrical bypass is?

Blower motor blew its fuse again. Truck was rewired, so not looking forward to trying to figure that one out.

I'm about to order parts, just want to make sure I got everything

Drier
orifice tube
o rings
cycling switch
schrader valves
compressor - seems I'm unable to find the appropriate Sanden compressor. Their listings only go back to '96, and other sites don't tell you part numbers or fitment.

I will probably take it to a shop to get it done, if I can find one that actually wants to do the work.

 

[Trucksareforwork]

Anyone know what the electrical bypass is?

Blower motor blew its fuse again. Truck was rewired, so not looking forward to trying to figure that one out.

I'm about to order parts, just want to make sure I got everything

Drier
orifice tube
o rings
cycling switch
schrader valves
compressor - seems I'm unable to find the appropriate Sanden compressor. Their listings only go back to '96, and other sites don't tell you part numbers or fitment.

I will probably take it to a shop to get it done, if I can find one that actually wants to do the work.

I think that’s it for parts assuming your hoses are good and will fit the compressor you are ordering.

Oil
Refrigerant
Flush fluid and a way to flush it

 

[RaisedK5]

Looks like that one that is bypassed is the thermostatic switch.

You must be registered for see images attach

 

[Steppin Razor]

Thank you

Does anyone know what brand the LMCtruck compressor is? It seems I'm unable to find out from the online sellers which Sanden compressor would work, so it's either the unit from LMC or a Four Seasons one from Rockauto.

 

[BurbanPena]

R12 and r134a are compatible all you need to do is get the shrader valve conversion kit rent a evacuation pump and gauges from o’reillys put a vacuum on the system and charge with r134a make sure you get the cans that don’t have the pag oil in it you will also use les freon because r134a is more dense so you will need to look up a calculator that will tell you how much r134a compared to r12