ac thread

[CAVANALK5]

Hey guys I know this is a cold thread [pardon the pun], but I saw no sense in starting a new one. How's your respective systems and methods holding up since your last post?

Its still up to mid 90's during the day here in Oklahoma but I'm only puttering my Blazer 5 miles to and from work a couple days here and there so its no issue now. Starting to cool off in the evenings too. But I want to gradually gather parts and supplies over the winter and install to get ready for next sweltering summer.

AC hasn't been operative since late 1990s in my Blazer. I think my father said compressor locked up. Whatever it was was going to be several hundred dollars at that time it wasn't the family's primary vehicle. The belt is removed from compressor and he been since that time. Spins freely by hand with no noise. All other parts intact but unsure of condition. We do not speak now so no asking him. This thread has given me quite a few options to think on.

Thanks in advance. Hope y'all have a great week!

 

[Fordum]

Real quick, no cost, check.
Open the hood, turn the ignition on, have someone turn the AC on and off with the fan on low. You should hear the compressor clutch clicking on and off. If it does, that means the system has pressure. If it does not click, then that is as far as you can go at this point. Probably out of gas, although it could be a bad wire or fuse.
If it does click, turn the compressor clutch on, and try to turn the pulley in the direction the belt would turn it. If its solid and will not turn at all, then the compressor is locked up. If it turns some, then the compressor is not locked solid. It might still be bad, but its not frozen.

At that point, you have gone as far as you can go without gauges and tools. But you may know more than you did before. Don't forget to turn the ignition back off. Don't need a dead battery tomorrow.

 

[Blue85]

Just to add to Fordum's post above. If the clutch doesn't engage, it's kind of hard to turn the compressor by hand. However, without a belt attached, there is no harm in engaging the clutch just to make sure the compressor turns. Look at the clutch to be sure the 2-pin connector is attached. Do the same for the pressure switch attached to the receiver/dryer (silver can near the evap box). If this is all there, engaging the clutch should be as simple as unplugging the connector from the pressure switch and jumper between the two sockets (piece of wire or something). Don't jumper the blades of the switch itself (does nothing) and don't jumper the connector on the clutch (could pop the fuse).

If the clutch clicks (and you'll see it pull in against the pulley), the electrical side is fine. If not, get a voltmeter and measure the voltage inside the big connector that goes to the pressure switch. One of those terminals should be 12V when the dash switch is set to A/C.

You can also use a DMM to measure the pressure switch. Reading should be low, like 1 Ohm.

 

[CAVANALK5]

Awesome. Great info guys. This will get me started for sure. Thank you!

 

[CAVANALK5]

Just to add to Fordum's post above................[section removed to save space]

Blue85, just for my education...am I jumping to give the illusion to the compressor that sufficient pressure is present?

Thanks again to you and Fordum for taking the time to give a nice in-depth reply. Makes me glad I finally renewed my subscription.

 

[Blue85]

If the clutch doesn't engage through the switch, but does engage with the jumper, either the switch is bad or you're out of refrigerant. But with it engaged, you can verify that the clutch works, the rest of the wiring works and the compressor "feels" OK.

 

[Fordum]

Exactly. I was getting fancy and trying to do more than one test at a time. The idea was to check for pressure by seeing if the clutch engages, then check to see if the compressor was locked up if the system had pressure. But, I should have continued on like Blue85 did. With my test, if the system was empty then you never got to check the compressor.
But, even if the system is empty, you can jumper the switch and try to turn the compressor.

 

[midnitewarya]

Hey guys I know this is a cold thread [pardon the pun], but I saw no sense in starting a new one. How's your respective systems and methods holding up since your last post?

Its still up to mid 90's during the day here in Oklahoma but I'm only puttering my Blazer 5 miles to and from work a couple days here and there so its no issue now. Starting to cool off in the evenings too. But I want to gradually gather parts and supplies over the winter and install to get ready for next sweltering summer.

AC hasn't been operative since late 1990s in my Blazer. I think my father said compressor locked up. Whatever it was was going to be several hundred dollars at that time it wasn't the family's primary vehicle. The belt is removed from compressor and he been since that time. Spins freely by hand with no noise. All other parts intact but unsure of condition. We do not speak now so no asking him. This thread has given me quite a few options to think on.

Thanks in advance. Hope y'all have a great week!

When the heat hit over 100, I found my system was having a hard time at idle. I added an electric fan to the radiator pack, centered over the evaporator. That did the trick. Six months of 100+, and it's still blowing like ice. With the 134a...