2001 Chevy Truck A/C PROBLEM

2001 CHEVROLET TRUCK
323,651 MILES • V8 • 2WD • AUTOMATIC
Avatar
MTRDUDE
  • MEMBER
  • 51 POSTS
Chevy 3500 series, 6.5 diesel with a refrigerated food delivery body on the back. Replaced the A/C accumulator, liquid & suction hoses & a new condenser with a new orifice tube. Vacuumed system for one hour & let sit for 30 minutes, no leakage. Charged the system manually by bypassing low pressure switch. Filled system to recommended 2 lbs. R134a and got 38 degrees from vents but low pressure gauge never showed above 10 psi; high pressure gauge showed 150-180 psi. Plugged in low pressure switch; comp. clutch cycles 2-3 seconds on then off for 3-4 seconds then repeats, cannot get compressor to cycle longer than that.
Sep 24, 2008 at 7:28 AM
Advertisement
Avatar
2CARPRO JACK
  • CERTIFIED EXPERT
  • 11,533 POSTS
Sounds like it is low if it is cycling like that.Ambient temp can play a role in thepressures, so the 2 lbs they say may not be an exactly corect amount. Get the high side up to 200 with engine hot and see what happens.Low side should be around 35
Sep 24, 2008 at 7:46 AM
Avatar
MTRDUDE
  • MEMBER
  • 51 POSTS
I'll check that and see. What do you think of the possibility that the low press switch is bad given the age & mileage of the vehicle?
Sep 25, 2008 at 6:50 AM
Advertisement
Avatar
2CARPRO JACK
  • CERTIFIED EXPERT
  • 11,533 POSTS
That is possible as well, its just that the low side pressure sounds a little bit low.But you are correct, they did have some problems with the cycling switch (low side). Easiest way to se if the system has enough in it is to hold the engine around 2500 rpms adn see if the comp stays on
Sep 25, 2008 at 7:46 AM
Avatar
MCAUTODOC
  • MEMBER
  • 33 POSTS
Thanks for the help. I won't see the truck till Friday so I'll try that then & then maybe add a little more 134 to see if the pressure comes up. If none of that works I'll replace the low press. switch. I have another guestion about a different vehicle; can I ask that here or do I need to go back through the procedure first?
Sep 25, 2008 at 12:30 PM
Avatar
2CARPRO JACK
  • CERTIFIED EXPERT
  • 11,533 POSTS
What you got?
Sep 26, 2008 at 7:49 AM
Avatar
MTRDUDE
  • MEMBER
  • 51 POSTS
2001 Chevy Malibu w/ 3.1L. New brakes all the way around and ABS sensors & wiring look good/normal. ABS dash light coming on intermittently and when it does I get a noise, seems to be from under the dash. Have no diagnostic capability to read code(s) on ABS system, am assuming it's the motor making the noise?
Sep 26, 2008 at 7:56 AM
Avatar
2CARPRO JACK
  • CERTIFIED EXPERT
  • 11,533 POSTS
Most likely, but you will need a scan tool to find out.Sorry.It is req'd to pull the codes out of the ABS system
Sep 26, 2008 at 8:01 AM