LMTV Air Conditioner

[GeneralDisorder]

I reviewed the diagram. I guess you're right it only says "high" pressure switch. I don't see low pressure mentioned. Do they think you should assume that's a binary switch with both high and low pressure protection? It's hard to know if this engineer had thier coffee that day. Ha ha.

I don't think they worried about low pressure - they may have wanted the system to run even if it was slightly low on charge. But that's just a guess. I guess it could be a binary switch but I don't have any evidence one way or the other without asking Red Dot besides the nomenclature not mentioning any low pressure cut-out function.

 

[GeneralDisorder]

You know "your stuff", GeneralDisorder.

Out of curiosity, where did you pick all of that up?

Just picking up stuff along the way, or are you maybe a former HVAC tech?

I know enough to be dangerous with HVAC - I own a repair/performance shop and so to buy refrigerant and legally work on AC systems in vehicles you must complete SAE training to get the license or they won't sell you the stuff (in bulk anyway - you can buy small cans over the counter but not the 30lb cylinders). Then you have to buy a machine to properly recover the refrigerant - that was only $5,000 or so.

Also did some work with refrigerated (and desiccant) air dryers for commercial compressed air systems in a former career path. So I've stared way too long at refrigerant pressure and troubleshooting charts over the years. You pick things up.

 

[WassawBound]

Guys, I think I'm going to throw parts at this AC system, flush it and see it I can get it running again. I think at a minimum I'll replace the TXV expansion valve, the drier and the binary switch. Does anyone have part numbers for those items?

Will any universal drier do? My drier has no markings on it. The label is faded on the binary switch too. Most of these kits include the switch. What voltage is the switch, 24V?

What's the part number on the Gen 2 unit's expansion valve?

 

[jpelc]

Does any one know of a diagram for the RedDot GEN II evaporator unit? I am looking for an electrical diagram to figure out the connectors wiring designations. I found one but it shows two 4 pin connectors. I have one 4 pin and one 6 pin.
(the 12 pin plug shown connects with the included controller)

 

[GeneralDisorder]

Yes I can pull the diagram for that system. That's a later Gen II with the intelligent monitoring computer. I haven't installed one of those but it shouldn't be a huge deal.

 

[Keith Knight]

 

[jpelc]

Thanks Keith Knight, I do have that diagram. My challenge is I have 6 pin rectangular connector, not 4.

 

[jpelc]

Yes I can pull the diagram for that system. That's a later Gen II with the intelligent monitoring computer. I haven't installed one of those but it shouldn't be a huge deal.

So do you have a diagram for this unit? I'd love to see it!

 

[Another Ahab]

Does any one know of a diagram for the RedDot GEN II evaporator unit? I am looking for an electrical diagram to figure out the connectors wiring designations. I found one but it shows two 4 pin connectors. I have one 4 pin and one 6 pin.
(the 12 pin plug shown connects with the included controller)

Isn't that how it always works?!

 

[m-35tom]

I don't think they worried about low pressure - they may have wanted the system to run even if it was slightly low on charge. But that's just a guess. I guess it could be a binary switch but I don't have any evidence one way or the other without asking Red Dot besides the nomenclature not mentioning any low pressure cut-out function.

There is a low and a high pressure switch.

 

[Keith Knight]

Sorry I have 1st gen and 2nd gen diagrams. Not your newest version. But most likely you’ll be making new connections because most likely your truck harness was built before your air conditioner.

 

[jpelc]

Sorry I have 1st gen and 2nd gen diagrams. Not your newest version. But most likely you’ll be making new connections because most likely your truck harness was built before your air conditioner.

Yes, you are quite correct. I have A0 that did not have AC at all. I was prepaired for that until I discovered that I have two more wires that are not on this diagram: Black/White stipe and Orange. I am guesing it is for the new protector box for some sensors. I am concerned that that protector will prevent the unit to work w/o those/this sensor.

 

[Keith Knight]

Hopefully general disorder will come up with something. He’s our wizard and magically finds data unavailable to us mortals.

 

[GeneralDisorder]

 

[GeneralDisorder]

That's gonna be fun to figure out! The computer uses transducers and controls the clutch itself. Lovely. I would rip that off and rewire it as a trinary switch system. Otherwise call Red Dot and bend over till you can kiss the ground.

 

[GeneralDisorder]

Yes, you are quite correct. I have A0 that did not have AC at all. I was prepaired for that until I discovered that I have two more wires that are not on this diagram: Black/White stipe and Orange. I am guesing it is for the new protector box for some sensors. I am concerned that that protector will prevent the unit to work w/o those/this sensor.

You are fundamentally correct. It's not a protector - it's literally controlling the whole system and has direct control over the compressor clutch so unless you get the transducers it's expecting and put them where it expects them - expect it to not function.

 

[Keith Knight]

Now why would they go and make it more complicated?

 

[Keith Knight]

Yes, you are quite correct. I have A0 that did not have AC at all. I was prepaired for that until I discovered that I have two more wires that are not on this diagram: Black/White stipe and Orange. I am guesing it is for the new protector box for some sensors. I am concerned that that protector will prevent the unit to work w/o those/this sensor.

Do you have that sensor?