Frequently Asked Questions About GMC General Truck Heat & AC Parts

Will these heat and AC parts fit my specific GMC General truck model and year?

Our heat and AC parts are designed for GMC General trucks manufactured between 1977 and 1987. Most components like heater cores, blower motors, and AC compressors are compatible across these model years. However, some parts may have variations between early models (1977-1980) and later models (1981-1987). Always check the product description for specific year compatibility, or contact our customer service team with your VIN number for exact fitment verification.

How difficult is it to replace the heater core in my GMC General, and what tools do I need?

Replacing a heater core typically requires 3-5 hours for someone with moderate mechanical experience. You'll need to drain the coolant, remove the dashboard components, and disconnect the heater hoses from under the hood. Essential tools include a socket set, screwdrivers, pliers, drain pan, and new coolant. The most challenging part is accessing the heater box behind the dashboard. We recommend having a service manual handy and setting aside a full day for the job if it's your first time.

Why is my GMC General's AC blowing warm air even after recharging the system?

If your AC still blows warm after recharging, the issue likely involves failed components rather than just low refrigerant. Common culprits include a faulty compressor clutch, worn compressor, leaking evaporator core, or clogged expansion valve. Start by checking if the compressor clutch engages when you turn on the AC. If it doesn't, test the clutch relay and pressure switches. Many GMC General owners find that replacing the entire compressor assembly solves chronic AC problems more effectively than repeated repairs.

Are aftermarket blower motors as reliable as OEM parts for my GMC General?

Quality aftermarket blower motors can match or exceed OEM performance when sourced from reputable manufacturers. Look for motors with sealed bearings, balanced fan cages, and proper amp ratings (typically 15-20 amps for GMC General trucks). The main difference is often the warranty period - OEM parts may offer longer coverage. Many customers report excellent results with aftermarket motors that cost 40-60% less than OEM. Just ensure the motor matches your truck's specific mounting configuration and electrical connections.

What's involved in converting my GMC General from R-12 to R-134a refrigerant?

Converting to R-134a requires replacing several components for proper operation. You'll need new O-rings compatible with R-134a, a new accumulator/drier, proper conversion fittings, and PAG oil instead of mineral oil. The system should be thoroughly flushed to remove old oil residue. While conversion kits make this feasible, expect about 15-20% less cooling efficiency compared to the original R-12 system. Many GMC General owners find the conversion worthwhile given R-12's limited availability and high cost. Professional evacuation and charging equipment is recommended for best results.