A/C Help
#1
07-23-2013, 10:47 PM
Join Date: Jul 2013
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A/C Help
Thanks in advance for any input... .
Background:
Just bought the truck yesterday. The guy told me in advance the A/C would be cold for the first 10-15min. then would slowly get warmer. So when I test drove it that's what happened.
When looking at the truck I noticed what appears as someone's patch job on the high pressure line so I figured it probably leaks there and is low on coolant.
I buy the truck and bring it home.
Today I stop and get a can of R134A with the gauge on it. So with the truck running and the AC on high I hook it up to the low pressure line. The gauge only reaches about 20psi so I open the valve and slowly fill it to about 50psi. Close the valve and disconnect the can. Go around to the truck and sure enough ice cold air.
I drive the truck around the road maybe 10min and the air starts to get warm again.
Go back home, pop the hood and now notice the compressor is not kicking on. After a short time checking to make sure everything is connected properly I decide to put the can of R134A back on the low line and immediately the gauge shoots up to like 90psi. Unhook it, put it back on and bam 90psi...
So my guess is somehow I have way to much pressure in the line and maybe the pressure switch is not allowing the compressor to kick on? And what should I do???
Thanks again for any help.
Sorry for the long story
Background:
Just bought the truck yesterday. The guy told me in advance the A/C would be cold for the first 10-15min. then would slowly get warmer. So when I test drove it that's what happened.
When looking at the truck I noticed what appears as someone's patch job on the high pressure line so I figured it probably leaks there and is low on coolant.
I buy the truck and bring it home.
Today I stop and get a can of R134A with the gauge on it. So with the truck running and the AC on high I hook it up to the low pressure line. The gauge only reaches about 20psi so I open the valve and slowly fill it to about 50psi. Close the valve and disconnect the can. Go around to the truck and sure enough ice cold air.
I drive the truck around the road maybe 10min and the air starts to get warm again.
Go back home, pop the hood and now notice the compressor is not kicking on. After a short time checking to make sure everything is connected properly I decide to put the can of R134A back on the low line and immediately the gauge shoots up to like 90psi. Unhook it, put it back on and bam 90psi...
So my guess is somehow I have way to much pressure in the line and maybe the pressure switch is not allowing the compressor to kick on? And what should I do???
Thanks again for any help.
Sorry for the long story
#2
07-23-2013, 10:55 PM
What year is the truck?
You only get an accurate pressure reading when the compressor is running. When it isn't, the high side/low side pressures will slowly equalize. 90 PSI when the compressor ISN'T running is probably close to normal. Would be interesting to see what high side pressure is doing when the compressor quits.
Take it out, drive it around with the A/C on, until it starts blowing warm. Drive another five minutes. Check the compressor, see if it is running. If it isn't, put a jumper in the low side pressure switch, see if it runs. If it doesn't, do the same with the high side switch. If it runs, don't leave it that way... could get far to exciting. Replace the switch that bypassing makes it work. If neither one will make it go, try swapping the a/c relay in the PDC (black box behind battery) with another one. See if that makes any difference.
You only get an accurate pressure reading when the compressor is running. When it isn't, the high side/low side pressures will slowly equalize. 90 PSI when the compressor ISN'T running is probably close to normal. Would be interesting to see what high side pressure is doing when the compressor quits.
Take it out, drive it around with the A/C on, until it starts blowing warm. Drive another five minutes. Check the compressor, see if it is running. If it isn't, put a jumper in the low side pressure switch, see if it runs. If it doesn't, do the same with the high side switch. If it runs, don't leave it that way... could get far to exciting. Replace the switch that bypassing makes it work. If neither one will make it go, try swapping the a/c relay in the PDC (black box behind battery) with another one. See if that makes any difference.
#3
07-23-2013, 11:10 PM
Join Date: Jul 2013
Posts: 11
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What year is the truck?
You only get an accurate pressure reading when the compressor is running. When it isn't, the high side/low side pressures will slowly equalize. 90 PSI when the compressor ISN'T running is probably close to normal. Would be interesting to see what high side pressure is doing when the compressor quits.
I know I shouldn't have done this, but....
during my problem solving after the recharge I took a screw driver and pressed the nozzle on the High pressure line for just an instance and there was no pressure on that side?
Take it out, drive it around with the A/C on, until it starts blowing warm. Drive another five minutes. Check the compressor, see if it is running.
The compressor hasn't kicked back on since my joy ride after the recharge so it doesn't get cold at all anymore.
If it isn't, put a jumper in the low side pressure switch, see if it runs. If it doesn't, do the same with the high side switch. If it runs, don't leave it that way... could get far to exciting. Replace the switch that bypassing makes it work. If neither one will make it go, try swapping the a/c relay in the PDC (black box behind battery) with another one. See if that makes any difference.
You only get an accurate pressure reading when the compressor is running. When it isn't, the high side/low side pressures will slowly equalize. 90 PSI when the compressor ISN'T running is probably close to normal. Would be interesting to see what high side pressure is doing when the compressor quits.
I know I shouldn't have done this, but....
during my problem solving after the recharge I took a screw driver and pressed the nozzle on the High pressure line for just an instance and there was no pressure on that side?Take it out, drive it around with the A/C on, until it starts blowing warm. Drive another five minutes. Check the compressor, see if it is running.
The compressor hasn't kicked back on since my joy ride after the recharge so it doesn't get cold at all anymore.
If it isn't, put a jumper in the low side pressure switch, see if it runs. If it doesn't, do the same with the high side switch. If it runs, don't leave it that way... could get far to exciting. Replace the switch that bypassing makes it work. If neither one will make it go, try swapping the a/c relay in the PDC (black box behind battery) with another one. See if that makes any difference.
Truck is a 2001 with the 5.9V8