QuestionQUESTION: I have an 04 Sierra 1500 4X4. Yesterday I turned on the the A/C and got nothing. Bought some freon to charge it but the freon was full. Took it to a dealer and they said the clutch coil for the A/C was not engaging. They said the magnet was not strong enough to engage the A/C. Dealer cost for repair is $900, is there a cheaper fix? I bought the truck only a month ago, of course dealer said no warranty was available.
ANSWER: looks like the part can be bought for between $140.00 and 170.00, installation is rather tricky as a special tool is required to remove the old clutch and install the new one. SOunds like the dealer was pricing out a whole new compressor. How many miles are on the truck? if the mileage is relatively low you could try calling GM customer assistance and opening a case
---------- FOLLOW-UP ----------
QUESTION: My Sierra has 130,000 miles on it. Thanx for the quick response.
Last week I was hauling a trailer with railroad ties (about 3000 lbs.), I pressed the button on the side of the gear selector for tow/haul and nothing happened. Could this be a fuse or a sensor issue? I checked the fuses under the dash and hood but found nothing. If it is a sensor where should I start looking and what is the cost of replacing?
Thanx
Answer
Tow Haul
not sure that it is a sensor, as pressing the button changes the way the trans shifts, could be a failure in the trans or the button itself, I can do some digging though, email me at tph617@email2me.net
here is a flow chart and picture of the circuit, looks like it runs through the BCM
Tow/haul mode enables the operator to achieve enhanced shift performance when towing or hauling a load. When tow/haul mode is selected, the tow/haul switch input signal to the body control module (BCM) is momentarily toggled to zero volts. This signals the powertrain control module (PCM) to extend the length of time between upshifts and increase transmission line pressure. Cycling the tow/haul switch again disables tow/haul mode and returns the transmission to a normal shift pattern.
Diagnostic Aids
If the electrical circuit tests are OK and the tow/haul shift pattern is not occurring, there may be a mechanical/hydraulic condition that prevents tow/haul operation. Refer to Symptoms - Automatic Transmission .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step tests for a faulty tow/haul switch.
This step tests for voltage input from the BCM to the tow/haul switch.
This step tests for ground integrity.
Tow/Haul Switch/Indicator Always On or Inoperative Step
Action
Values
Yes
No
1
Install a scan tool.
Turn ON the ignition, with the engine OFF.
Cycle the tow/haul switch while observing Tow/Haul Mode on the scan tool.
Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again?
--
Go to Intermittent Conditions in Engine Controls - 4.3L or Intermittent Conditions in Engine Controls - 4.8L, 5.3L and 6.0L
Go to Step 2
2
Remove the connector from the tow/haul switch.
Using the J 35616 GM Terminal Test Kit, install a fused jumper wire from the tow/haul switch signal and ground circuits of the tow/haul switch connector.
Does the scan tool Tow/Haul Mode indicate a status change?
--
Go to Step 7
Go to Step 3
3
Using the DMM and the J 35616 , measure the voltage at the tow/haul switch signal circuit of the tow/haul switch connector.
Is ignition voltage measured?
--
Go to Step 6
Go to Step 4
4
Using the DMM and the J 35616 , measure the voltage at the tow/haul switch signal circuit of the body control module (BCM).
Is ignition voltage measured?
--
Go to Step 5
Go to Step 8
5
Test the signal circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 9
Go to Intermittent Conditions in Engine Controls - 4.3L or Intermittent Conditions in Engine Controls - 4.8L, 5.3L and 6.0L
6
Test the ground circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 9
Go to Intermittent Conditions in Engine Controls - 4.3L or Intermittent Conditions in Engine Controls - 4.8L, 5.3L and 6.0L
7
Replace the tow/haul switch. Refer to Shift Lever Replacement in Steering Wheel and Column.
Did you complete the replacement?
--
Go to Step 9
--
8
Test the BCM for proper operation. Refer to Diagnostic Starting Point - Body Control System in Body Control System.
Did you find and correct the condition?
--
Go to Step 9
--
9
After the repair is complete, observe Tow/Haul Mode on the scan tool display, while cycling the tow/haul switch.
Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again?
--
System OK
Go to Step 1
