AC code 09
Thread Starter
Racer
Joined: Feb 2004
Posts: 426
Likes: 85
From: Rockwall TX
AC code 09
1990
low freon detected
low side is 60 psi
jump the coil and coil engages then drops to 25 psi
low pressure switch jumped and no change
system is all original, was blowing cold last year
AC relay is good.
no other codes
I replaced the water pump over the winter and the compressor lines got flexed, wonder if I lost freon there
FSM says add 1lb freon.
I have 1 can R12 14oz on the shelf and vintage gauge set
Before I tap into it, anything else to check? thanks
low freon detected
low side is 60 psi
jump the coil and coil engages then drops to 25 psi
low pressure switch jumped and no change
system is all original, was blowing cold last year
AC relay is good.
no other codes
I replaced the water pump over the winter and the compressor lines got flexed, wonder if I lost freon there
FSM says add 1lb freon.
I have 1 can R12 14oz on the shelf and vintage gauge set
Before I tap into it, anything else to check? thanks
Drifting
Joined: Jun 2013
Posts: 1,957
Likes: 342
From: Shell Point (Crawfordville) Florida
Are you measuring the low side pressure with the AC running or off?
If the compressor is running, 25 psi is too low and you need Freon. If 60psi was a static pressure it really doesn't mean anything.
Jumping the low pressure switch will cause the compressor to engage when the AC is turned on and that is done when the pressure is too low to allow the compressor to engage on its own.
The usual place for a leak is the high pressure Schrader fill valve or one of the seals at the compressor where the hoses attach. Either get a leak detector or put some UV dye into the system when you refill it with Freon to see if you can find the leak. Or keep refilling it every so often when needed.
I had to refill mine a few times 'till I found the high pressure fill valve was leaking and I replaced it with a new one for $3 or so from Autozone.
If you bother to do that, once you open the system you have to evacuate it and then totally refill it. Or just add your can of Freon till the low pressure reaches 45 lbs. with the system running.
You cannot add Freon to refill it unless the compressor is running just using one of those cans. You may need to jump the low pressure switch to engage the compressor, and then you can remove the jumper and reconnect it normally once you get high enough pressure in the system.
If the compressor is running, 25 psi is too low and you need Freon. If 60psi was a static pressure it really doesn't mean anything.
Jumping the low pressure switch will cause the compressor to engage when the AC is turned on and that is done when the pressure is too low to allow the compressor to engage on its own.
The usual place for a leak is the high pressure Schrader fill valve or one of the seals at the compressor where the hoses attach. Either get a leak detector or put some UV dye into the system when you refill it with Freon to see if you can find the leak. Or keep refilling it every so often when needed.
I had to refill mine a few times 'till I found the high pressure fill valve was leaking and I replaced it with a new one for $3 or so from Autozone.
If you bother to do that, once you open the system you have to evacuate it and then totally refill it. Or just add your can of Freon till the low pressure reaches 45 lbs. with the system running.
You cannot add Freon to refill it unless the compressor is running just using one of those cans. You may need to jump the low pressure switch to engage the compressor, and then you can remove the jumper and reconnect it normally once you get high enough pressure in the system.
