GMC S15 A/C Compressor Clutch Guide: 1982-1990
Everything you need to know before replacing the A/C compressor clutch on your 1982-1990 GMC S15.
- Confirm the clutch is the problem, not the compressor, by listening for noise with the A/C on and off.
- New OEM parts are not available; a quality aftermarket brand like Four Seasons is the standard repair.
- You MUST match the new clutch to your truck's specific compressor and belt type (V-belt vs. Serpentine).
- DIY replacement is possible but requires a special A/C clutch puller tool and snap ring pliers.
Is Your S15 A/C Clutch Failing?
A failing A/C compressor clutch on the 1982-1990 GMC S15 can cause several distinct symptoms. Because the clutch pulley is always spinning with the engine, some signs can be present even when the A/C is turned off.
Common Failure Symptoms:
- Grinding or Squealing Noises: A loud grinding or squealing noise from the engine bay that changes with engine RPM is a primary symptom. If the noise is present when the A/C is off, the pulley's bearing is likely failing. If the noise only occurs when you turn the A/C on, the clutch plates or internal compressor parts could be the issue.
- A/C Blows Warm Air: If the clutch fails to engage, the compressor will not run, and your system will only blow ambient or warm air. You may hear a 'click' when you turn on the A/C, which is the relay sending power, but the clutch itself does not lock.
- Intermittent Cooling: The A/C may work sometimes and not others. This can happen if the clutch coil is weak or the air gap is too large, preventing consistent engagement. Tapping on the clutch might temporarily make it engage.
- Visible Wobble or Damage: You may be able to see the outer plate of the clutch wobbling while the engine is running (use caution). In severe cases, the bearing can seize, which can damage the drive belt or the front of the compressor.
Don't Ignore a Noisy Clutch
A seized clutch bearing can destroy your drive belt, leaving you stranded. It can also cause damage to the compressor itself, turning a smaller repair into a much more expensive one.
Choosing the Right Aftermarket Clutch
For a vehicle like the 1982-1990 S15, new original equipment (OEM) parts from GM are effectively discontinued. The standard and most practical repair is to use a new aftermarket part. Used OEM parts from a junkyard are an option, but you risk getting a part that is near the end of its life.
OEM vs. Aftermarket
- OEM (Original Equipment Manufacturer): New OEM clutches are no longer available through dealers. Any parts found are likely New Old Stock (NOS) or used, with no warranty.
- Aftermarket (Four Seasons): Brands like Four Seasons are the industry standard for A/C repairs on older vehicles. They manufacture parts that meet or exceed original specifications and are widely available. While quality can vary with any aftermarket part, Four Seasons is a reputable choice for keeping your S15's A/C running.
Common Ordering Mistake: Know Your Compressor!
Over its production run, the GMC S15 used different A/C compressors. Early models (approx. 1982-1986) often used A6-style compressors with a V-belt, while later models used R4 or other types with a multi-groove serpentine belt. You must visually inspect your compressor and belt type before ordering a new clutch to ensure a perfect match. Counting the grooves on the pulley is a simple way to verify.
A/C Compressor Clutch Replacement Cost
Replacing just the clutch is more affordable than replacing the entire compressor assembly because you may not need to evacuate and recharge the A/C system. The cost depends on whether you do it yourself or hire a professional.
| Component/Service | Estimated Cost |
|---|---|
| New Aftermarket A/C Clutch (Four Seasons) | $130 - $205 |
| Shop Labor | $150 - $375 |
| Total Professional Installation | $280 - $580 |
Costs are estimates and can vary based on your location and local labor rates. This does not include a potential A/C system recharge if required.
Frequently Asked Questions (FAQ)
Should I replace the whole compressor or just the clutch?
If only the clutch bearing is noisy (noise is present with A/C off) and the A/C cools properly when it engages, replacing just the clutch is a cost-effective repair. If the compressor itself is noisy when engaged, leaking, or has seized internally, you must replace the entire compressor assembly, along with the accumulator and orifice tube, and flush the system.
Is replacing the A/C clutch a DIY job?
It can be, but it requires special tools. You will need a specific A/C clutch puller/installer kit and snap ring pliers to remove and install the clutch assembly. While it can often be done without opening the refrigerant system, access can be tight. It is a moderately difficult job for an experienced DIYer.
Can I drive my truck with a bad A/C clutch?
If the bearing is just noisy, you can drive it, but the bearing will eventually fail completely. If the bearing seizes, it can snap the drive belt, which may also run your power steering, alternator, and water pump. If the belt breaks, the truck will quickly overheat and lose power steering, so it's best to replace a failing clutch as soon as possible.
Were there any recalls for the A/C clutch on the GMC S15?
No, there are no specific NHTSA recalls or Technical Service Bulletins (TSBs) for the A/C compressor clutch on the 1982-1990 GMC S15. Any issues are addressed as individual repairs.
Technical Specifications
OEM Part Numbers: 89018807 1520019 1520078 1520304 1521539
Varies by year and engine. Early models may use a single V-belt, while later models use a 6-groove serpentine belt. Visual confirmation is required before ordering.
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 S15: