I have this little issue that showed itself yesterday. The blower for the Heat/AC won't turn off no matter what the setting on the Heater Control Module. Let me rephrase that; It won't do anything but blow at maximum speed.

Today, I went through the service manual to troubleshoot it and the DTC it throws is a Blower Motor Circuit code. I went through all of the test steps in the service manual(with exception of the blower motor relay as it's obviously getting power), and the car passed every single test without solving the problem. My initial suspicions lied in the control module on the dash, however the motor still runs with the module unplugged.

My new suspicions lie with the Power Transistor unit, even though all the tests show that it is still good. When it is plugged in, even without the wires from the control unit, it will still run.

The evap core was full of water recently due to the drain hose being kinked, so maybe it got wet and is shorted out internally?


Does anyone have any ideas?

 

hmm so nobody has ever had any issues similar to this?

 

Bump.Sorry no me I know We need Super Negcamber or Super Billman 250 !!

 

maybe just the fan relais sticking

grtz kristof

 

Sounds like you have a short somewhere in the circuit. Do you have a wiring diagram?

 

I do have the diagram, and I tested all of the connections for continuity and good grounds. I think I'll try to get ahold of the heater control from another car and see if it doesn't fix it.

Strange thing is that I was using it just fine the other night, and the next morning it was acting all crazy...

 

Shorted MOSFET in the fan control module. It's a fairly common RSX problem - applies to the S2000, too.

Replace the MOSFET itself (desolder the old one, solder in a new one) and you'll have a working blower for ~$3.

http://forums.clubrsx.com/showthread.php?t...lower+motor+out

This is what the innards of the module look like - in that thread, they're bypassing the thermal fuse (not a good idea!). You will want to replace the black 3-pinned transistor-looking device with a new one.

 

But the problem is you have continuity where you shouldn't. So you need to see on the diagram where there should and shouldn't be continuity. A short is a constantly grounded circuit. If the module or switch only sends power when you turn the blower on, when its off you should have no continuity.

 

Wow thanks! That thread is describing exactly the same problem I am having. I had suspected the power transistor module, so I guess when the drain tube was clogged the unit got wet and shorted out.

I'll post back with updates