Experiencing insufficient heat in your Chevy Colorado can be frustrating, especially during colder months. If you’re noticing that your truck isn’t blowing hot air as expected, or the temperature is inconsistent, you’re likely facing a common HVAC system problem. Fortunately, many of these issues can be diagnosed and sometimes even resolved with a bit of troubleshooting. This guide focuses on two frequent culprits behind inadequate heating in Chevy Colorados: thermostat malfunctions and issues with the HVAC temperature control cable.
One of the primary reasons for a lack of heat can be a faulty thermostat. The thermostat’s role is to regulate engine temperature by controlling coolant flow. If the thermostat is stuck in the open position, coolant continuously circulates through the radiator, preventing the engine from reaching its optimal operating temperature. A telltale sign of a stuck-open thermostat is a temperature gauge that struggles to rise, often staying around the quarter mark or lower on your dashboard indicator even after driving for a while. If your temperature gauge consistently reads near the halfway point under normal driving conditions, it’s less likely that the thermostat is the source of your heating problem.
Another common issue, particularly in older Chevy Colorado models, involves the temperature and mode control cables. These trucks utilize a cable-operated system for HVAC controls. Over time, these cables can become disconnected, either at the bellcrank on the HVAC case or at the back of the HVAC control panel itself. Additionally, the outer sheath of the cable can detach from its retainer at either end, disrupting the control mechanism. In some instances, the bellcrank might even “jump” a tooth, leading to the temperature door not moving fully in either the hot or cold direction.
To inspect the temperature control cable end near the glove box, begin by opening the glove box door. Locate the stops on the sides of the glove box and push them inward to allow the glove box to swing down completely. Looking inside and towards the left, you should be able to spot the end of the temperature control cable. Pay close attention to the outer sheath and ensure it is securely seated within its retainer, as shown in the image below.
For a more comprehensive check, you’ll need to examine the bellcrank located on top of the HVAC case. This requires removing the trim surrounding your radio and HVAC controls. While the exact removal process might vary slightly depending on your Colorado’s model year and trim, you’ll likely need to carefully pry off the trim pieces to gain access. It may be necessary to partially remove the radio or HVAC control unit itself for clear visibility of the bellcrank. Once you have access, you should see a mechanism similar to what’s depicted in the following images. These images illustrate the bellcrank positions for full cold and full hot settings. Examine the teeth alignment and movement as you adjust the temperature control knob in your cabin.
While specific images of the cable connections at the back of the HVAC control panel aren’t provided here, you can expect the connection style to be similar to those observed at the bellcrank. By systematically checking these thermostat and control cable points, you can effectively troubleshoot and pinpoint the cause of your Chevy Colorado’s heating problems, potentially leading to a DIY fix or providing valuable information for your mechanic.
