Skip the auto shop - Our mechanics make house calls

Q: heating/cooling sysytem

asked by on

Back a couple months ago my motor blew so I got a new motor and resistor for my car thinking that would fix the heating/cooling problem but it didnt so what could be the problem ?

A: In the future, it helps if you include your...

In the future, it helps if you include your car's year, make, and model. On all cars there are a few few other components involved in the blower motor circuit on your car.

Blower motor switch: This can be in the form of a automated module that controls the temperature, mode and blower speed. This type of system would be found on luxury cars. It can also be a simple four position switch. There are a few other configurations that are a combination of the two, but in every case, there is a switch, either automated or manually controlled that will send power to the resistor that controls fan speed.

Whenever we are testing an electrical circuit, the first thing that should be done is check all the fuses. Not just the fuses in the circuit, gut all the fuses. It is often difficult to know if another fuse powers a part of the circuit you are working on, even when it isn't labeled as such. The simplest thing to do is to test all the fuses. If you find a blown fuse, you will need a factory wiring diagram to determine what it supplies power to.

Connectors commonly get hot and melt in this system. If you find a connector at the resistor, blower motor or blower motor switch, (keep in mind the switch could be a module, I don't know because I don't know what kind of car you have) that has been hot or melted, this will create a high resistance in the circuit and electricity won't flow. Even if the connection looks good to the human eye, electricity doesn't flow based on what we thing we see. The flow of electricity occurs at the atomic level.

If you decide to get this fixed I suggest getting your car looked at by a certified technician, such as one from YourMechanic, who can diagnose your A/C issue and make the necessary repairs.

I hope this is helpful to you.

Good luck!

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: When i have my car running with my heat or ac on my car hesitates like it wants to stop when i'm stopped at a light.

As you may know, your car's AC system when working properly puts an extra load on the engine at all times when it is running. When this happens, your car's computer makes adjustments to compensate for this extra load on...

Q: The front passenger floor board in my car is damp, and the windows fog up on the inside

Have the A/C system checked to see if the drain is clear for the A/C evaporator case. If you park under or around trees that shed a lot then it can get debris into the A/C and clog the drain,...

Q: My mustang keeps dying.

Hey there. There is a fuse in the fuse junction box within the engine fuse box that needs to be checked. It is a 20amp fuse. There are two fuse link wires that go from junction box to the alternator....

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.