Ac gurus need a quick answer

[chris142]

Looking at the web page it appears these units use a thermostatic switch with a capillary tube that senses evaporator temperature. This switch will turn the compressor off and on dependent on the evaporator temperature to regulate the temperature. Cycling has to happen on this type of system.

You may have to buy an adjustable thermostatic switch. I failed to comprehend that it's an under dash unit.

 

[typ4]

The reality is you have a small system, big compressor and its being very efficient. The evap cutting off the power is doing so because its cold enough, keep in mind an under dash unit recycles cab air, if you were getting some outside air it would take more to cool and run longer cycle times.
The low side should drop with rpm. I didnt see which one was dropping.

 

[BrianX128]

Yeah I took everything apart today and blew compressed air through the whole system there are no restrictions. I put it back together with the old condenser after pressure testing it the one that came with the kit is so small I didnt even have a good plan for mounting it.

Put it all back together pulled a vaccuum again and put in one can 12 oz and the adapter for the new "pressure release" cans broke. The funny thing is, it works better with one 12oz can as far as cycle time at rpms then it did with 24 or 36..

Seriously these instructions are also a joke. When I get a chance tonight I'll upload the pics more spelling mistakes then 3rd grades and the page for the suggested freon levels just says psi no oz measurements. So I guess get it to hit 35 at idle and stop? Well see how it performs today its 84 sunny humid and I have 5 errands to run with the fiance I dont want to do. Hope they can be done with water on the floor cause i only drilled one drain in the floor so far

 

[BrianX128]

So I have 16 oz in the system and it doesnt cycle at all anymore. Its not as cold of air as it was at 35+, but I'd rather have air that is 85-90% close to that cold and the system on at all times then what I had before.

It's just strange. The pressure switch was never turning it off and I havent seen it do anything yet it was always the evaporator cutting it off. Even now with it working at all times it will have 25psi at idle and 10 at rpms sometimes at 8 when I accelerate the engine quickly but it doesn't shut off. I'm not sure what the pressure switch even does at this point.

I'm just glad it's working and it worked this way for 40 minutes and nothing was frosted over or odd looking so I think I'll leave it be.

I have to figure out this drainage issue in the cab though or I'm gonna drown. +1 for rubber vinyl floor and not carpet.. lol

 

[hce]

It's just strange. The pressure switch was never turning it off and I havent seen it do anything yet it was always the evaporator cutting it off. Even now with it working at all times it will have 25psi at idle and 10 at rpms sometimes at 8 when I accelerate the engine quickly but it doesn't shut off. I'm not sure what the pressure switch even does at this point

Not strange but exactly how this system is intended to work. Cutting power to the compressor is the only way for this type of system to regulate vent temperature.

 

[gnathv]

There should be a nipple formed in your case. May have to drill a hole in it and put tubing on it and run through floor

 

[BrianX128]

It stayed on for another half hour drive the entire time but was still only 85% as cool I'd say. I put a 7 second shot of refrigerant in and it felt a bit cooler on a ten minute drive, gave it one more 7ish second shot of refrigerant and drove it 40 minutes home. I'd say it was 95ish percent cool as before when it was on when it was cycle happy. Towards the end of that last trip the last five minutes it did start to occasionally cycle but the cab was cold. I threw my override switch for the heck of it and it still would run and wasnt so cold it was frosting over.

Short of routing my water out of the cab when it runs I think were as good as were gonna get. My only gripe with this system is the lack of directions for stuff anyone would need to know ac pro or not. Showing a 134a chart isn't the same as saying fill to approx 16-18oz of refrigerant for optimal cooling and compressor may cycle when vent temps are cool so do not overfill.. but hey its working

 

[chris142]

Is your suction line ice cold? If it is then that part is ok.

 

[BrianX128]

Yeah. It seems happy today in some real crazy humidity were getting here with 24oz in it. Cycles some when its 70 out but keeps the cab cold and doesn't shut off when its 85 and disgusting outside.

You must be registered for see images attach

So I had the water issue from the condensation in the evaporator, I hooked the hoses up and got them routed out the cab floor. Fun times before I did that as you can see.

Only other issue I'm having is the suction line and expansion valve area gets condensation on it and drips on the floor as well. I dont have a great plan for that yet.. ideas welcome.

 

[DrCharles]

Try some "No Drip tape" (asphalt sticky stuff)... that's what it's made for

 

[BrianX128]

That stuff looks neat I'll have to try it. I can definitely get it on the hoses and pipe going in the evaporator.

I think the actual expansion valve itself is going to be my biggest challenge. It gets condensation a lot and it's not an easy shape to put tape on.

 

[typ4]

I don't know why you're fixated on it cycling that's how these systems work you have a brand new system that's designed around old technology if it's charged properly it's going to short cycle for all the reasons I stated in my previous post.

 

[BrianX128]

It's not that I'm trying to get it to not cycle ever, but after you mentioned about the cycling I did some digging with other users who had this system and the general consensus is since the evaporator shuts off when it is "too cold" you want to get the system charged up to where at the hotter side of temps you see in your area (in pa 85-90f) it is almost but not quite that cold. That way at hotter days like today at roughly 90 degrees it's blowing super cold air but not to the point where it shuts off and the cab starts to warm up while its off. Yet when it's only 70 outside it will be too cold and cycle then.

I guess the thing is, I had it so overfilled when you mentioned the cycling being normal before, that it was frosting over internally after only running for 15-20 seconds at high rpms because it was running too efficient and when it went in its "warm up period" it would stay off so long the air coming out of it really wouldn't be cold anymore.

Your 100% right with the cycling, it's just the way I had it cycling before led me to believe it was under-filled and broke and needing more of a charge when it was really just overfilled and running too efficient, but not practical.