Climate Control flashes

  • 2004 GMC C1500
  • V8
  • 4WD
  • 60,000 MILES
GMC Sierra Pickup. My AC climate control flashes the snowflake symbol when I turn it on and will not work. The problem is intermittant and random sometimes it works fine and other times it doesn't. It has gotten more frequent though.
Do you
have the same problem?
Thursday, October 16th, 2008 AT 12:01 PM

1 Reply

Hi Jmes,

I can only provide information on how to go about testing for intermittent faults so you have to do it yourself.

Tools Required
J 35616 GM-Approved Terminal Test Kit
J-38125 Terminal Repair Kit.
J 42675 Flat-Wire Probe Adapter.

Most intermittent conditions are caused by faulty electrical connections or wiring. Inspect for the following items:

Wiring broken inside the insulation
Poor connection between the male and female terminal at a connector.
Poor terminal to wire connection-Some conditions which fall under this description are poor crimps, poor solder joints, crimping over the wire insulation rather than the wire itself and corrosion in the wire to terminal contact area, etc.
Wire insulation which is rubbed through-This causes an intermittent short as the bare area touches other wiring or parts of the vehicle.
Refer to Inducing Intermittent Fault Conditions in order to duplicate the conditions required in order to verify the complaint.
Refer to Testing for Electrical Intermittents for test procedures to detect intermittent open, high resistance, short to ground, and short to voltage conditions.
Refer to Scan Tool Snapshot Procedure for advanced intermittent diagnosis.

Testing for Proper Terminal Contact

It is important to test terminal contact at the component and any inline connectors before replacing a suspect component. Mating terminals must be inspected to ensure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation.

Contamination may be caused by the connector halves being improperly connected. A missing or damaged connector seal, damage to the connector itself, or exposing the terminals to moisture and dirt can also cause contamination. Contamination, usually in the underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit.

Deformation is caused by probing the mating side of a connector terminal without the proper adapter. Always use the J 35616 when probing connectors. Other causes of terminal deformation are improperly joining the connector halves, or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact causing an open or intermittently open circuit.

Round Wire Connectors

Follow the procedure below to test terminal contact of Metri -Pack or 56 series terminals. Refer to the J- 38125 or the J 38125-4 Instruction Manual for terminal identification.

Follow the procedure below in order to test terminal contact.
1. Separate the connector halves.
2. Visually inspect the connector halves for contamination. Contamination may result in a white or green build-up within the connector body or between terminals. This causes high terminal resistance, intermittent contact, or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals, and connector body.
3. Using an equivalent male terminal from the J-38125, test that the retention force is significantly different between a good terminal and a suspect terminal. Replace the female terminal in question.

Flat Wire (Dock and Lock) Connectors

There are no serviceable parts for flat wire (dock and lock) connectors on the harness side or the component side.

Follow the procedure below in order to test terminal contact.
1. Remove the component in question.
2. Visually inspect each side of the connector for signs of contamination. Avoid touching either side of the connector as oil from your skin may be a source of contamination as well.
3. Visually inspect the terminal bearing surfaces of the flat wire circuits for splits, cracks, or other imperfections that could cause poor terminal contact. Visually inspect the component side connector to ensure that all of the terminals are uniform and free of damage or deformation.
4. Insert the appropriate adapter from the J 42675 on the flat wire harness connector in order to test the circuit in question.
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Friday, October 17th, 2008 AT 9:27 AM

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