Diagnosing cabin heater problems pass gas in spanish

Winter is nearly upon us and before you know it, you’ll be regularly using the heater in your car again. Before the cold sets in, though, it’s a good idea to check your in-cabin heater to be sure you’ll have heat when you need it. Here is what you can do to test your heater and then diagnose any problems you might have if you’re not getting heat. Better to fix it now, before it gets cold.

Start with a test of your vehicle’s heater. This is easy to do. Just drive the car normally and, once the engine is at operating temperature, turn on the heater. If it’s still warm outside, you can do this with the car in your driveway or a parking lot so you don’t have to sit inside and roast. Let the heater run for a while and make sure it continues to blow heat through all vents, including the defroster vents at the windshield and side windows. If all is well, you’re good to go this winter!

Obviously, is no air is blowing through the vents, you don’t have heat (or A/C, for that matter). There are two things that could be happening here. Either your blower motor is not operating or the internal vents that allow airflow from the blower to the cabin vents are not opening.

If that is not the problem, locate the blower motor in the engine compartment. It’s usually located on the firewall on the opposite side of the engine from the brake master cylinder. Check your repair manual as some cars have more than one and some are located under the dash.

Once you’ve located the blower motor, check its circuits both from the power source (battery) and the control module and switch on your control panel in the cabin. This will be a relatively complex series of wiring, starting from the power source to the keyswitch, fuse box, control switch, and fan. Make sure there is continuity to and from everything on the circuit.

If the fan is working and blowing, but you are not getting air blowing through the vents, then you likely have problems with the vents. Inside your dashbaord are a series of tubes that pipe around to each of the outlets (vents) where the heat (or A/C) comes out into the passenger cabin. These are controlled by internal vents that open and close (often to varying degrees) to allow air to flow through. If those vents do not open and close, the blower cannot push air through to the cabin.

On most modern cars, the vents are controlled electronically by actuators (small electric motors). Older cars will have them manually controlled through levers from the dashboard climate controls. Either way, if something is not working, the vents won’t open and no air will blow through. Check all of the fuses for your climate system before you dig in.

On most vehicles, the bottom of the dashboard can be removed to locate the heater core – or the area of the venting system that houses it. Use your repair manual to find the core and get as close to it as you can without getting too involved in the disassembly process. You want to get to where the vent tubing that houses it is so that you can test those actuators on the vents that surround the heater core.

In this scenario, you have air blowing through the vents and into the cabin, but that air is not heating up. This problem is almost certainly a lack of hot water getting to the heater core. It could also be a heater core vent problem if the air coming out is lukewarm but not hot – in that case, see the above on vent actuators.

The heater core works by receiving hot engine coolant from the engine’s cooling system. The core itself is a small radiator over which air is blown to heat it up before it is sent into the cabin. If hot water (coolant) does not get to the core, it cannot heat the air. The most common reason water does not get to the core is because there is a blockage in the heater lines running from the engine block to the heater core through the firewall. Often, a flush and replace of the coolant in the engine will remedy this. Follow the instruction manual for your vehicle to do this properly and be sure to allow the engine to completely cool down before you do this.