Chevy Blazer Heater, Gauges and 4WD Drive Problems

Chevy Blazer. My heater won’t work but nothing’s leaking can u please help me.

Answer: With the heat not working, I’ll have to assume you mean it just blows cold air instead of not blowing at all. If you have no heat, you probably have a restriction somewhere in the system, or a cooling system component not functioning properly. Corrosion and old coolant can clog up thermostats, radiators, and heater cores causing no heat to come out of the vents. You might want to start with a cooling system flush and go from there. You can use a garden hose also to manually backflush the heater core. Remove both hoses at the firewall and run the water full blast in one and then in the other and watch for the water to start to clear up. You could also be looking a bad water pump, or internal engine problem causing air to be in the system which would lead to no heat.

Gas Gauge

1999 Blazer. My gas gauge and my temperature gauge quit working after I replace my battery.

The gauges not working after you replaced the battery is probably due to when you installed the battery. You could have accidentally touched one of the cables where it shouldn’t go and popped a fuse, or burned a wire or fusible link. I’d start by checking fuses under the hood and in the dash to see if any are blown. Check all of them. Check the battery cables and any attaching wires or fusible links. Fusible links are down by the starter. Worse case scenario, you blew the instrument cluster and it will need to be replaced or removed and sent out for repairs.

4 Wheel Drive

My 1999 Chevy Blazer has a history of 4wd problems. I’ve had it ”fixed” twice but then

it only works once and then won’t engage. Someone told me that this model 4wd had a design problem, something to do with a ”heat probe”? I’m clueless. Any advice?

Answer: As for the 4WD problem, there is no ‘heat probe’ on your vehicle. I’m not sure where you heard that or who told you, but that is absolutely incorrect. If the system is not engaging, it could be anything from the transfer case to front differential, the electrical components, etc. There could be issues with the transfer case control module, which is located in the lower right kick panel area.

There has been issues with water getting into the module and causing problems. Replacement of the TCCM and then fixing the water leak into the truck would be needed. Also, the 4WD switch could be bad. As you can see, there are many, many things that can cause the 4WD not to engage. You probably want to get it checked out.