Pressure's down in system.Refill the system one can at a time of refrigerant.If one can fores the clutch and gets cold inside,good to go.Too much refrigerant will hamper the temperature and will stay low.Not cool.So one at a time.
SOURCE: AC panel messed up compressor doesn't come on.
check the fuse first then check the wiring inside then that is OK then check the wire on the compressor it self, its a connector might have to pull it off and then on. pulling off the compressor is a big deal its lines are a sealed system, the refrigerant lines are under pressure
You must of lost freon and when there is no freon your clutch will not activate.Must check it for pressure in the lines.If there is pressure check pressure switch.Good luck let me know
SOURCE: can't get clutch to engage on air contioner.
Back by the firewall on the passenger side of the truck, the accumulator has a two wire plug and pressure sensor. If you jump remove the plug and jump the two points while the ac is set to on and the engine is running. Check to see if the compressor kicks off. If it runs then you have either low freon or a bad sensor.
SOURCE: 1991 Sie rra GMC AC control problem
this will happen if the system senses low charge. This doesnt mean that is the problem the low pressure switch or cycling switch on the accumulator/dryer on passenger side firewall will also keep in from coming on. this can be checked by jumping the system there.If you jump it and it comes on and air is cold on both sides of cab this could definately be the problem.
SOURCE: 1991 Sierra GMC AC control problem
The follwing is a cut and paste from a service bulletin:
Bulletin No.: 461202
Date: May, 1994
SUBJECT:
A/C CONTROL HEAD FLASHES OR ERRATIC OPERATION OF A/C CONTROLS (POLISH
TERMINALS)
MODELS:
1988-94 CHEVROLET AND GMC TRUCK C/K MODELS
1990-94 CHEVROLET AND GMC TRUCK TOPKICK/KODIAK MODELS WITH C60 OR C69 AIR
CONDITIONING
CONDITION:
A/C Control Head flashes, performs erratically or malfunctions.
CAUSE:
Light surface corrosion on the Control Head terminals.
CORRECTION:
Remove the A/C Control Head and while holding the unit with the terminal
cavity down (toward the floor) so no particles will fall inside on the
circuit boards, polish the terminals on both sides of the cavity with a lead
pencil pink eraser. Do not use an ink eraser or other abrasive such as a
small wire brush or sandpaper, etc. Doing so will remove the terminal
coating and degrade the contact surface.
Performing this procedure, in many cases, will make replacing the Control
Head unnecessary. Using this procedure in conjunction with the A/C circuit
diagnosis found in the Electrical Diagnosis Manual and especially before
replacing a Control Head for any reason is recommended.
After polishing the Control Head terminals, but before reconnecting, check
for proper terminal contact as described in the applicable electrical
diagnosis manual. If contact is good, apply dielectric grease (P/N 12345579)
to the harness connector terminals. Please do not apply grease to the
Control Head.
208 views
Usually answered in minutes!
×