Thermostat placement RV2 compressor

[Mako21]

I’ve tried contacting Original Air for tech support, but have been waiting for a call back or even email for over a couple weeks now. I’ll ask here and maybe someone can help.

Long story short I had my RV2 overhauled and am converting to R134. I purchased the Original Air thermostat kit and am trying to figure how to install/wire this thing up. Can anyone offer advice? Here is thekit:
1961-79 MOPAR A/C Thermostat Switch Kit 134A

Thanks.

 

[j_anderson]

That probe on that part goes into the AC Evaporator and is mounted on the outside case of the heater/AC box under the dash

 

[Mako21]

The probe goes into the evaporator? Through an opening somewhere? Or just push it in anywhere between the fins?

I’m confused about the mesh screen and O ring included in the kit also. What do we do with that?

Also what electricals are you unplugging and plugging into the thermostat unit itself?

I assume the sticky tape is to mount the unit on the dash?

 

[j_anderson]

I’m not sure about how theirs mounts. I’m just showing how/where the factory one mounts. There is a hole in the side of the heater box where the probe slides in and through the evaporator. The factory unit also activates a cable. It’s possible theirs mounts somewhere else?

 

[Dantra]

I’ve tried contacting Original Air for tech support, but have been waiting for a call back or even email for over a couple weeks now. I’ll ask here and maybe someone can help.

Long story short I had my RV2 overhauled and am converting to R134. I purchased the Original Air thermostat kit and am trying to figure how to install/wire this thing up. Can anyone offer advice? Here is thekit:
1961-79 MOPAR A/C Thermostat Switch Kit 134A

Thanks.

View attachment 1716204286

I'm somewhat facing the same questions myself.. but a totally different scenario. I'm doing a Hemi swap. But last year, I did do a complete revamp, upgrading to a sanden style compressor kit from Original Air and it came with that thermostat. I opted not to use it at the time because I knew there was already a thermostat in the box that also acts a compressor switch.. so I just left things as is. The switch allows current to the compressor (with a binary switch in there somewhere) but also has the thermostat built into it that allows for it to thermally shut off if it detects a freeze. So the switch is kinda needed or the compressor will just run no matter what the temp is set at.. you can here the switch click as you slide the temp up and down.

The aftermarket switch can be added to the firewall and the probe can be carefully wrapped around the low side (larger) fitting and tube coming out of the firewall. Clean the fitting and metal tube portion of that line with scotch bright, sand paper, wire etc brush prior to wrapping the probe around it. DO NOT kink the probe. Use a small hose clamp and lightly clamp it in place, holding it firmly to the tube. Use the black butyl tape to wrap around the fitting and probe to insulate it from engine heat. The wire that runs to the compressor will need to be cut and routed through the switch.. 1 terminal is power in and the other is power out. Basically cut the wire in two, put female terminal on each end and plug it into the switch... direction doesn't matter. I'm not sure about that filter tho.

The way I'm thinking of doing it is to put the probe in it's original placement in the evap core. I've read that it only needs to go in a few inches (giggity). It's a hard spot to get o but since my column is loose right now, it might not be too bad. But, the original switch needs to remain wired and the wire just needs to be cut after the switch and routed through the new thermostat. I'll just move the original probe up outta the way somewhere and mount the new switch someplace convenient .

Not sure if you have looked into condensers but you might.. more efficient The 134 condensers are pretty reasonable from Bouchillon . I actually ended up getting something else since my build is a different animal, but you might look into it.

ac multipass condensers - Bouchillon Performance Engineering

 

[slantsixdan]

The probe goes into the evaporator? just push it in anywhere between the fins?

Yes, that's one way to do it. Not the best way; that placement is more for OE clutch-cycling switches adjustable by a dashboard slider or knob. This what you've got isn't that kind of switch.

I assume the sticky tape is to mount the unit on the dash?

No, that's insulating tape. It's for if you decide, rather than drilling holes in the box under the dash, to put the the clutch-cycling thermostatic switch (which is what this is) in the engine bay. If your low-side line doesn't have an available capillary tube tunnel on the metal part near the firewall (either because there is none or because it is occupied by the expansion valve's capillary tube), you wrap the CCTS' capillary tube around that metal part of the low-side line, then insulate it from the outside world by overwrapping it with the tape.

This is the better way to do it; you want the CCTS to sense the temperature at the tail end of the evaporator, not at some random middle point. It is also the easier way by far, and it allows ready access to the adjustment screws on the CCTS, with which you set the cut-in and cut-out points to optimize the system's performance.

It is also the intended way.

I’m confused about the mesh screen and O ring included in the kit also. What do we do with that?

Looks like that's meant to go where the EPR valve used to be, in the compressor where the rear (low-side) fitting bolts on. Remember, you need to remove the EPR valve when converting to R134a and installing a CCTS.

Also what electricals are you unplugging and plugging into the thermostat unit itself?

This CCTS goes in series with the power feed to the compressor clutch. So, you splice it into the wire going to the compressor clutch.

If you want to be smart and preserve your hard-and-expensive-to-find mode selector (and reduce the risk of a fire), you add a relay to the clutch circuit so the wire leading to the clutch goes to a new relay mounted conveniently in the engine bay, and the relay powers the clutch. That way the wires and switches inside the car (and the bulkhead terminals) handle only low current, and the relay does the heavy lifting on the other side of the firewall.

Relay hookup is easy. Start with a good, reliable brand of 4-terminal relay. Terminal 30 goes to ignition-on +12v via a fuse of the same rating as the one presently protecting the A/C clutch circuit.

Terminal 87 goes to the clutch.

Terminal 86 gets the present clutch wire.

Terminal 85 goes to ground.