Vehicle make/model = Chevy Silverado
Year = 1995
Mileage = 158,000
Engine size = 305ci
dash lights = nope
codes = nope
work done prior = none
work done to repair = none
tech = JK
question = Hello JK. Please help me, I'm at my wit's end. My '95
Chevy truck is having AC/vent problems.
The fan speed and fan work correctly. The heater control and heating
work correctly.
The fresh air/recirc button never illuminates or has any affect. The
AC button never illuminates or turns on the
AC compressor. The vent selector has no affect. Air only comes out of
the floor vent, regardless or the setting.
I just replaced the dash control unit with a new one, and it didn't
change the symptoms at all. I checked and even checked continuity on the
related fuses.
I jumped the AC high pressure sensor and it didn't change a thing. I
hotwired the AC compressor on, and nice cold air blew out of the vent
immediately, so I assume the AC system is working correctly. I've gotten
in the dash and reseated all the plugs I could reach. When I swap
between the new and old control units nothing changes at all.
Once in a while one of the servos will move, but rarely. The air might
come out of the upper dash vents when I first start the truck but
switches to floor vent within a couple seconds. Sounds like one of the
other flaps might move once in a while, but rarely.
Can you please tell me if these symptoms ring a bell with you, of at
least offer a suggestion on how to troubleshoot this thing?
JK:
Sounds like you have several different problems here. For the vents switching, sounds like a
vacuum problem. There is a vacuum reservoir tank that hold vacuum to move the vents
actuators. If vents switch when hitting gas, or when idling, then need to find source of vacuum
leak. Either the tank or the hose that feeds the switch.
The compressor not coming on is electrical. There is also a low pressure switch, a compressor
relay for the system. Make sure to check ALL fuses also.
Back
Year = 1995
Mileage = 158,000
Engine size = 305ci
dash lights = nope
codes = nope
work done prior = none
work done to repair = none
tech = JK
question = Hello JK. Please help me, I'm at my wit's end. My '95
Chevy truck is having AC/vent problems.
The fan speed and fan work correctly. The heater control and heating
work correctly.
The fresh air/recirc button never illuminates or has any affect. The
AC button never illuminates or turns on the
AC compressor. The vent selector has no affect. Air only comes out of
the floor vent, regardless or the setting.
I just replaced the dash control unit with a new one, and it didn't
change the symptoms at all. I checked and even checked continuity on the
related fuses.
I jumped the AC high pressure sensor and it didn't change a thing. I
hotwired the AC compressor on, and nice cold air blew out of the vent
immediately, so I assume the AC system is working correctly. I've gotten
in the dash and reseated all the plugs I could reach. When I swap
between the new and old control units nothing changes at all.
Once in a while one of the servos will move, but rarely. The air might
come out of the upper dash vents when I first start the truck but
switches to floor vent within a couple seconds. Sounds like one of the
other flaps might move once in a while, but rarely.
Can you please tell me if these symptoms ring a bell with you, of at
least offer a suggestion on how to troubleshoot this thing?
JK:
Sounds like you have several different problems here. For the vents switching, sounds like a
vacuum problem. There is a vacuum reservoir tank that hold vacuum to move the vents
actuators. If vents switch when hitting gas, or when idling, then need to find source of vacuum
leak. Either the tank or the hose that feeds the switch.
The compressor not coming on is electrical. There is also a low pressure switch, a compressor
relay for the system. Make sure to check ALL fuses also.
Back
| Was this information helpful? Is this what you have been searching for? Why not make a small donation to help keep us going. The guys work hard everyday to try and help people like you searching for help on the web. LEARN HOW |
