• Welcome to H4O! For a reduced ad experience, please login or register with the forum.

A/C cooling issues

Kyle

Well-Known Member
Messages
1,707
Location
Santa Clarita, CA
okay, update on the situation. if i turn the ac on, the compressor kicks on, stays on for 20 seconds then starts turning off and on really fast like every 2 seconds the compressor kicks on and off, on and off. and its a real heavy hit on the engine too, ill rev the engine to 1500rpm and as soon as the compressor kicks on the engine will bog down to 1000rpm. could there be to much pressure in the low side causing the compressor to have to work harder and the compressor kicks on and works then realizes there to much pressure and kicks itself off? im just about to give up and go without ac. (sunroof open,windows down)
 

Kyle

Well-Known Member
Messages
1,707
Location
Santa Clarita, CA
update again. i went out, did the ac recalibration thing (again) and the air gets cold as hell when the compressor is on for a few seconds then goes to not hot but "cool" so i decided to drive it around to see what it felt like on the road with air running passed to condenser and it was "cooler" but everytime the compressor kicks on and off on and off it gets cold as balls and the air starts staying cold. its defiantly better than before, im wondering if its still low on freon hence the cooling but not full cold and the compressor kicking on and off.

Edit: im skeptical about adding more freon because the gauge on the canister is in the red psi zone, i dont want that **** blowing up in my hand and taking it off. and yessss im wearing eye protection, hearing protection, and gloves.
 
Last edited:

alrock

El Diablo
Staff member
Messages
10,650
Location
Scottsdale
I think you have too much pressure in there. Take it to a shop and have it done right. As F5 pointed out, it will likely only be about $100-$120 to do it right. It's probably one of the best bang for the buck services.

That said, I did play with that A/C Pro R134a in a can today in the Haudi. A/C was running warmish with the air temp about 64 degrees. PSI was low at 35. Boosted it up to about 52 psi and temps dropped to 58 degrees. Six degrees may not sound like much but it was enough to take the air from cool to cold.

Before I did the A/C Pro I did a lot of reading and it appears to be a common issue with people putting in too much refrigerant due to the crappy gauges on these cans. My gauge wasn't working right. I put in a little and the gauge didn't move. I put in more, and the gauge didn't move. Three or four disconnects, a couple of restarts, and suddenly the gauge showed me around 52 psi. It appears very easy to screw things up; I think I got lucky.
 

Kyle

Well-Known Member
Messages
1,707
Location
Santa Clarita, CA
yea the gauge on mine is ****ed up, it added to much in and overpressured the system, i "accidentally" push the valve down and let a little bit out. after "accidentally" pushing it down a few more tomes the ac compressor started staying on longer and longer until now it stays on for a decent amount of time. im going to take it to shop tomorrow and have them do everything right for me.
 

Reineke

Member
Messages
8
Location
Van Alstyne, TX
Okay soo after testing I've found that if I let the car sit for an hour. Come back and start it up the air blows cold for about 20 mins then the compressor starts kicking on and off on and off. I'm thinking low freon, so the compressor turns off to save it self then the freon psi builds back up and the compressor kicks on until the Psi drops again and it cuts off again? Thoughts?

I'm not sure if you fixed this or not, but I am having a similar experience. I put my gauge on and the pressure was reading low, so I added. The compressor started to cycle more, so I stopped and took it to a shop. I paid $73 to have them evacuate the system, vacuum it out, then recharge to the proper level (so it's definately the way to go). They said the system was slightly overcharged. When I got the truck back, it wouldn't blow cold, just slightly cool. I swapped out the relay and looked at the electrical connections and all were good. I decided to put my gauge back on it and it read 0. Long story short, before heading back to the shop to chew ass, the next day, I put my gauge on another vehicle and it read fine. I put them back on the H3 and it read low, like before, but would actually blow cold air.

Now, to the fun part. I discovered that our AC systems have a Thermal Expansion Valve (TXV). When the TXV starts going bad, it can cause the compressor to pull a vacuum on the low side or at least have a lower pressure that it should have. The low pressure causes the compressor to kick on and off and when it has a vacuum, it's not going to cool at all.

I have an appointment on Wednesday to get this part replaced. Will update once completed.
 

Kyle

Well-Known Member
Messages
1,707
Location
Santa Clarita, CA
I'm not sure if you fixed this or not, but I am having a similar experience. I put my gauge on and the pressure was reading low, so I added. The compressor started to cycle more, so I stopped and took it to a shop. I paid $73 to have them evacuate the system, vacuum it out, then recharge to the proper level (so it's definately the way to go). They said the system was slightly overcharged. When I got the truck back, it wouldn't blow cold, just slightly cool. I swapped out the relay and looked at the electrical connections and all were good. I decided to put my gauge back on it and it read 0. Long story short, before heading back to the shop to chew ass, the next day, I put my gauge on another vehicle and it read fine. I put them back on the H3 and it read low, like before, but would actually blow cold air.

Now, to the fun part. I discovered that our AC systems have a Thermal Expansion Valve (TXV). When the TXV starts going bad, it can cause the compressor to pull a vacuum on the low side or at least have a lower pressure that it should have. The low pressure causes the compressor to kick on and off and when it has a vacuum, it's not going to cool at all.

I have an appointment on Wednesday to get this part replaced. Will update once completed.

thats exactly what was wrong with mine i swapped it and recharged the system and it blows soooooo damn cold!!!! i have to turn it down sometimes it gets sooo cold.
 

Jrkilburn

Well-Known Member
Messages
77
Location
Maryland
My AC has the exact same issue going on. I hope you guys have solved the mystery.


Sent from my iPhone using Tapatalk
 
Top