Why is my GMC Sierra heater not working?

Why is my GMC Sierra heater not working?

The most common reasons a GMC Sierra 1500 heater isn’t working are a broken heater blower motor, a problem with the thermostat, or a failed heater blower motor resistor.

Why is my heat blowing cold air in my car?

Low Coolant Level The coolant (usually a mixture of water and antifreeze) in your engine doesn’t just work to keep the engine from overheating: It’s also the source of heat supporting the heating system. If there isn’t enough coolant in your system, the heater core will blow cold air into your car.

What are some of the GMC Sierra heater problems?

One of the most common (and inconvenient) problems with the GMC Sierra is when it has no heat coming from the heater. Not having a functioning heater makes driving much less comfortable, and can be a sign of certain issues. At the simplest level, there are two main reasons why the heater is not working.

Can a bad heater core cause no heat?

The heater core itself can go bad. Over time, they are known to clog and fail. If you have a heater core that clogged, it’s not going to be able to pass coolant through. Without the warm coolant going through it, there can be no heat. A bad heater core can also leak, so watch out for that.

How do I know if my GMC Sierra thermostat is bad?

If your Sierra has a built in temperature gauge, take a look at it and see if it is in the spot it is normally in after a bit of driving. If it looks like it is colder than normal, that’s a pretty good indication that there is something wrong with the thermostat.

Why is my car heater not coming on?

At the simplest level, there are two main reasons why the heater is not working. If it’s not coming on at all, it’s usually either the blower motor or some other wiring issue. If the heat is blowing, but blowing cold, it has something to do with the coolant getting to the heater core, or the heater core itself.