How to repair GMC CK Series truck HVAC unit?

Use paper clips or wires to jumper across the switch connectors on the wire harness. Key on engine off, compressor clutch should “click”. If no click, check the wiring harness for open wires, functioning high pressure switch, and correct voltages. TESTING LOW PRESSURE SWITCH. With the truck running, A/C turned on.

Why is my Chevy c1500 suburban blowing hot air?

When the air conditioner in your 1996 Chevrolet C1500 Suburban starts blowing hot air, you likely have a freon leak. Recharging the freon in your AC system is an inexpensive and easy first step to restoring the cooling capacity of your A/C system.

How to add Freon to a 1996 Chevrolet C1500 suburban?

How to add freon to your 1996 Chevrolet C1500 Suburban: hook up the can of refrigerant (likely r-134a) to the low pressure port. When your compressor kicks on, add freon to the correct pressure. In addition to cooling, freon lubricates the compressor when it runs. Advance Auto coupon for 20% off entire order: KIOSK20 Author

Why is my HVAC not working on my Chevy Silverado?

Pull and reinsert the fuses for the HVAC before starting the truck. If this didn’t work for you try Step 2. If it seems like one side is stuck at one temperature only, it could mean the blend door actuator is no longer working. The actuator turns a door to switch between warm and cold air, but there are multiple actuators in your truck.

Why is the AC not working on my Chevy Silverado?

Learn if it’s a simple fix or time to seek out a trusted technician. Not your vehicle? Why Isn’t My A/C Working? What are common reasons my Chevrolet Silverado 1500 has air conditioning problems?

Why is my C-1500 AC not working?

If it’s low enough, the compressor will not even kick in. Just a thought before you start tearing things apart. Thanks. I only have an old R-12 gauge set, so I can’t actually test the refrigerant level.

What was the a / C problem on my 1998 Silverado?

One day last year, I started my 1998 C-1500 350 2WD, and surprise – the a/c blew hot air. I said a bad word. I only use the truck to go to the lumber yard, so I just let it be – until today, when it was 98F and I got stuck in a 10-mile traffic jam (I said many bad words).

What is the temperature control on a GMC CK truck?

Power is routed back out to Pin 7 through a 3.8 ohm resistor and the Max AC switch, but on a 1500 truck Pin 7 is not used. The Blend (temperature) door control is powered directly from +12V via Pin 5.

Where is the fuse box located on 1991 Chevy 1500?

1 answer 1994 chevy 1500 10 inch rear drum assembly diagram. 1 answer 1994 chevy 1500 10 inch rear drum assembly diagram. According to this diagram the horn relay has to be energized. Where is fuse box located on 1991 chevy pick up chevrolet 1991 k1500 question.

Where is the AC relay located on a GMC CK?

The AC Relay is located external to the controller. The coil of the AC relay is powered from the ECU, located on the left side of the engine bay. The High Pressure, Cycling, and Lo pressure refrigerant switches also go to the ECU. When all conditions are met, the ECU provides power to the AC relay coil, and the AC compressor clutch is energized.

Where are the fuses on a 1991 GMC c1500?

Electrical components such as lights, heated seats and radios all have fuses in your 1991 GMC C1500 Sierra 5.0L V8 Extended Cab Pickup. This free video shows you how to replace a blown interior fuse on a 1991 GMC C1500 Sierra 5.0L V8 Extended Cab Pickup

Why are the heater controls on my truck not working?

Went out to start the truck and the heater controls were black wont come on no heat or ac. I have checked the fuses all good I have also put two new controls in and nothing.

What kind of heater does a Chevy 1500 have?

I have a 1992 chevy 1500 4.3l 2wd. Went out to start the truck and the heater controls were black wont come on no heat or ac. I have checked the fuses all good I have also put two new controls in and nothing.

What causes a GMC CK HVAC unit to malfunction?

This is caused by an open Switched +12V power transistor, or it could possibly be caused by a defective blower speed switch. This is caused by a shorted Switched +12V power transistor, or it could possibly be caused by a defective blower speed switch.

When was the GMC C / K HVAC unit last used?

This Heater AC Control Unit was used on the 1996-98 line of Chevrolet and GMC C/K Pickups, and on 1996-99 GM Suburbans, Tahoes, and Yukons. It was no longer used after 1999, due partly to unreliability, and partly due to upgrades to newer technology.

Why does my GMC Sierra a / C compressor not work?

Add some freon to it “just one can for now” and see if the compressor will kick in. If it does add freon to it slowly till the high side goes to around 200 and the low side does not fall under 30. If it does not kick in let me know and we can go over he power and grounds and get the a/c to work again.

Why is my a / C compressor not working on my Chevy Silverado?

This condition may be caused by the A/C compressor clutch cycling out early when the low pressure side reaches approximately 380 kPa (55 psi). The fix is to bring the vehicle to the dealer to have the latest software installed into the vehicle. I hope this helps.

What to do if your a / C compressor won’t engage?

HOWEVER, if you cannot turn the compressor on, you cannot recharge your AC levels (grrrr). So you need to use a paper clip to bypass the relay switch and force the clutch to engage. You can then recharge the freon and re install the relay switch and it will sense more pressure and the clutch will engage by itself. Loading…

How to repair GMC CK Series truck HVAC unit?