AC & Heater complaints by model year
Which parts fail
Components named in complaints (air conditioning, heater, defroster, HVAC controls).
Mileage when the problem started
What owners report
The four wheel drive actuator on top of the transfer case failed- actuator is vacuum actuated and when it failed it allowed transfer case fluid to be drawn into the vacuum system of the vehicle causing problems with four wheel drive engagement and disengagement. But the worst problem is that the fluid caused the heater controls, also vacuum activated, not to work properly so that the vehicle windshield could not be defogged or defrosted, which is a safety problem because of the lack of visibility. It is a known defect with this vehicle but g.m. Refuses to acknowledge the manufacturing problems. The dealer had to replace all the actuators (5), the vacuum tank, the vacuum lines and the heater control.
At approximately 83,456 miles the heater core broke. I first noticed smell ethylene glycol, it caused (somewhat greasy) fogging of the windshield above the windshield heater vent. Glycol leak directly into the car, causing wet upholstery or carpeting. Coolant sprayed directly into the passenger compartment followed with white colored smoke.
This vehicle has had a problem with the defroster that began at under 20,000 miles. The dealer has attempted repairs twice under warranty. As I am once again having the problem, and off of the warranty, I began looking on the internet for information. It turns out that the transfer case vacuum switch goes bad and allows the fluid in the transfer case to be drawn up into the HVAC system. This causes, among other problems, the defroster to not operate. This is a very difficult and expensive problem to correct as the entire HVAC system must be flushed out and any bad parts replaced. This seems to be fairly common and yet GM will do nothing off warranty, and in my case did not correct the problem under warranty. I believe a recall is in order.
Consumer has brought vehicle back to the dealership three times for a creaking noise heard in the front end. Also, consumer complained that when taking foot off throttle vehicle will not slow down for a period of time. When driving with the air conditioner on, vehicle will not slow down. Vehicle overruns the cruise control from 3 to 6 miles per hour.
Consumer stated the seats failed to lock into position along seat tracks, and will move unexpectedly during normal operation, dealership has examined vehicle and was unable to effectively remedy the problem. Consumer also stated the center console lid was cracked, fan was inoperative.
At 65 degrees consumer rolled up the window and could feel heat coming from air conditioner vents. Dealer could not discover where the heat was coming from, and could not fix air conditioner. Please provide more information.
Letter from to the administrator re product safety recall 00V258001 affecting 2000 Chevrolet vehicles with the incorrect payload capacity listed on the vehicle certification label on the driver's side door. The consumer stated the label read 3,872 lbs, when it should have read 1,434 lbs. GM informed the consumer, they were not going to re-open the recall. Updated 03/02/12 the consumer also stated the heat stopped working in the vehicle. Updated 03/09/12 updated 04/20/12
Consumer states exhaust fumes and smog comes through ventilation system, there is no way to close vents or to stop fumes from coming inside, consumer also states the smells cause bad headaches and nausea.
Related recalls (1)
Visibility › Defroster/defogger/HVAC system
Vehicle description: light duty pickup trucks equipped with electric drive. Rapid fogging of the interior glass can occur within two minutes after the heat is turned on if (1) the outside temperature is between 35 and 76 degrees fahrenheit and (2) water has collected on the heat exchanger during previous operation of the air…
Remedy: Owners are being provided with a caution label and supplemental insert for their owner's manual advising them to follow a "stop and wait" procedure to help avoid window fogging while driving.
Frequently asked questions
Which Chevrolet S10 years have ac & heater problems?
By NHTSA complaints, the 1996 (16), 1995 (15), 1999 (10), 2003 (8) and 1998 (7) model years. AC & Heater complaints make up 2% of all complaints for the 1996.
Is there a recall for Chevrolet S10 ac & heater problems?
Yes — 1 recall, including 98V-177 (defroster/defogger/hvac system, Aug 4, 1998). Recall repairs are free at authorized dealers; check a specific car with the VIN recall check.
At what mileage do Chevrolet S10 ac & heater problems start?
Across all years, half of the complaints with a recorded mileage happened before about 47,000 miles; 62% happened before 50,000 miles.
What part fails most often?
Owners most often name the appliance › air conditioner (48 mentions), followed by the defroster/defogger/hvac system (14).
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.