• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Replacing blower motor control box

28 September 2004
Temple Terrace FL
Since winter is coming to Central Florida, on occasion I use my heater in the mornings. That said, when I cranked up the heat, it came on and would not shut down. The problem was diagnosed as a broken heater control. The cable was lifted on the blower motor and the valve was turned off to prevent heat from entering the cabin. The part I am replacing resides under the glove box to the right of the console. After of about a year of waiting, the part come in. Has anyone installed the part and if so, is there anything I should know? It looks to be straight forward with an electrical plug protection and a cable connection to the blower motor on the outside firewall. Lastly, since I only use the heater a few times a year, how easily should the control valve move? I am referring to the valve with the cable on it that mixes the hot water into the heater core. I was wondering if the hot water valve became sticky and took out the heater control? Any advise would be greatly appreciated. As my 2000 NSX is over 20 years old, the little things and difficulty of obtaining parts drives me up a wall sometimes. Thanks. Jerry
I must admit to being confused. On my car there is nothing under the glovebox except for the keyless control unit. There is a stack of control modules behind (actually 'forward' of) the glove box. The heater / evap assembly is more central. Because your problem seemed to be tied to the heater control valve I assumed that perhaps the 'heater control' you referred to was the air mix control motor which also controls the cable which operates the heater control valve. However; what also confused me was

It looks to be straight forward with an electrical plug protection and a cable connection to the blower motor on the outside firewall.

There is no cable connection from the air mix control motor to the blower motor unless you meant the mechanical cable connection to the heater valve, not the blower motor. Years ago I removed the complete center console to remove and do some work on my stereo head unit. I recall looking at the heater / evap assembly and as I recall I could see the air mic control motor and it is actually mounted on the bottom of the heater / evap assembly (see photo below)

Mix control motor.jpg

I didn't need to work on it so I didn't pay much attention to it. The R&R of the mix control motor from the heater / evap assembly as described in the service manual is straight forward and the only 'technical' bit is the adjustment of the heater valve cable which is not complicated. The service manual implies that the mix control motor and cable work can be done with everything in the car. I can't remember whether the mix control motor would be accessible with just the panels under the glove box removed (I expect not) or whether the center console has to come out. I expect that small hands and long fingers will be useful for an in-situ replacement.
Thanks for the quick reply, that is the part I am referring to in my post. The cable connects to the mix manifold valve on the firewall. I think I can access it without dismantling much. I am worried that the mix valve on the firewall side where the other end of the cable is frozen. I don't want to ruin my new part. I will move it manually and hit it with some penetrant oil first. Thanks from the "other old guy" Jerry
That sounds like a plan. If you disconnect the cable from the hot water valve you should theoretically be able to open and close the valve relatively easily. If it doesn't, add that to your replacement list.

Watching with interest as I also have a Myr 2000 and was hoping advanced decrepitude was still off in the future.
The entire dash definitely has to come out in order to remove the heater / evap unit. Aside from the agony of removing the dash you have the double agony of dealing with the AC system recharge when you disconnect the evap. Looking at the heater / evap unit, I think the mix control motor is accessible without removing the heater / evap unit. You probably need a low profile / mini ratchet that accepts screw driver bits to remove the mix control motor.