A/C Compressor Clutch Guide for 1985-1992 GMC Jimmy
Everything you need to know about replacing the A/C compressor clutch on your S-15 Jimmy.
- A bad A/C clutch is a common reason for no A/C in an '85-'92 Jimmy, with symptoms like warm air and grinding noises.
- You can often replace just the clutch without opening the A/C system, saving time and money.
- Verify your specific compressor type (e.g., R4) and belt style before ordering an aftermarket kit.
- For this vehicle's age, a new aftermarket clutch kit from a brand like Four Seasons is a practical and cost-effective repair.
Is Your Jimmy's A/C Clutch Failing?
When the air conditioning in your 1985-1992 GMC Jimmy stops blowing cold, the A/C compressor clutch is a common suspect. This part works hard and is exposed to heat and weather, leading to eventual failure. Understanding the signs of a bad clutch can help you diagnose the problem correctly.
🎬 Watch a general guide on diagnosing and replacing clutch bearings.Symptoms of a Bad A/C Compressor Clutch
- A/C Blows Warm Air: The most obvious symptom. If the clutch doesn't engage the compressor, the refrigerant won't circulate, and you'll only get warm air from your vents.
- Loud Noises: A grinding or squealing sound when you turn on the A/C can point to a failing bearing inside the clutch. If the bearing seizes, it can make a loud grinding noise.
- Clutch Doesn't Engage: With the engine running, have a friend turn the A/C on and off. Look at the front of the A/C compressor. The outer plate of the clutch should pull in and spin with the pulley when the A/C is on, and stop when it's off. If it doesn't move, the clutch coil may have failed or the air gap might be too large.
- Visible Damage or Burning Smell: Look for signs of burning or melted plastic around the clutch, which indicates an electrical failure. A seized clutch can also create friction and burn the serpentine belt.
Safety First: Refrigerant
Your Jimmy's A/C system contains refrigerant under pressure. If your system is from before 1993, it likely uses R-12 refrigerant, which is regulated and requires special handling. Many older vehicles have been converted to R-134a. Always wear safety glasses and gloves when working near the A/C system. It is recommended to have the system professionally evacuated before starting work.
Choosing the Right Aftermarket Clutch
For a vehicle like the '85-'92 Jimmy, finding a new OEM A/C clutch from GM is highly unlikely. The market is now served by aftermarket manufacturers. The key is choosing a reliable brand.
OEM vs. Aftermarket Quality: Original parts for these trucks were robust, but they are now decades old. A quality new aftermarket part is often a better choice than a used OEM part with unknown history. Brands like Four Seasons are major players in the aftermarket A/C world. While some forum users have mixed opinions on aftermarket parts in general, Four Seasons has been around a long time and is a common choice for repairs on older vehicles. For a straightforward part like a clutch on a simple A/C system, a new aftermarket kit from a reputable brand is a practical and reliable solution.
Pro Tip: Replace as a Kit
It is highly recommended to replace the clutch as a complete kit, which includes the pulley, bearing, and coil. The bearing is a primary failure point, and trying to replace just one piece is often more trouble than it's worth. A complete kit ensures all components are new and matched.
🎬 Learn how to install a new pulley and coil kit.Cost of Replacing Your A/C Compressor Clutch
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Clutch Kit (e.g., Four Seasons) | $133 - $203 |
| Shop Labor | $150 - $300 |
| Total Estimated Cost | $283 - $503 |
Note: Costs are estimates and can vary based on your location and specific repair shop rates. This does not include the cost of evacuating and recharging the A/C system, which may be required.
Frequently Asked Questions
Do I have to replace the whole compressor?
Not always. If the compressor itself is quiet and not leaking, you can often just replace the clutch assembly. 🎬 See how to replace the clutch without removing the compressor. This saves you from opening the refrigerant system, which avoids the need for evacuation and recharging. However, if the clutch failure was caused by the compressor beginning to seize, you will need to replace the entire compressor.
Is this a difficult job to do at home?
It's a moderately difficult job. You will need specific tools, including snap ring pliers and a special A/C clutch puller/installer tool. Access to the compressor on the S-15 Jimmy is generally reasonable from the top of the engine bay, but it can be tight.
What are the most common mistakes when ordering this part?
The GMC S-15 Jimmy used a few different compressors over its life. It's critical to verify which compressor your truck has (e.g., R4 or LTR4 type) before ordering. Also, check your pulley diameter and whether you have a serpentine or V-belt system to ensure you get the correct kit.
My clutch engages but the A/C is still warm. What's wrong?
If the clutch is engaging properly, the problem lies elsewhere in the A/C system. The most common cause is low refrigerant. It could also be a problem with the expansion valve, a clogged orifice tube, or an issue with the blend doors in your dashboard.
Helpful Videos
Technical Specifications
OEM Part Numbers: 1134346 88964864 6551217 6556715 89019188
Varies by compressor type (e.g., R4, LTR4), pulley diameter (e.g., 4.25"), and belt type (Serpentine or V-Belt). Visual confirmation is recommended.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- GMC Jimmy: