1994 Q45 air conditioner always on

[coolman]

I have a 1994 Q45 w/o touring. The problem I am seeing is that the air conditioner fan is turned on even though my air conditioner (A/C) is switched to the OFF position. I played with the A/C buttons, but the fan is still on. This problem started yesterday. Can anyone tell me the problem and/or explain what is going on?

[goody90q45]

A common problem, It sounds like it's time to replace your fan control amplifier (aka Darlington resistor). In addition to not shutting off is the fan running on high speed only?

Wes has step-by-step instructions for replacing it on his site at http://www.q45.org/darlington.html.

The amplifier is located behind the glove box and the entire job will take even the most novice of mechanics less than an hour to complete. As I remember the amplifier assembly was about $55 from the dealership and 25% less from Joe. Good luck.

[Q45tech]

The speed control failed because the fan motor is old and is overheating the controller............if you plan on keeping car replace the fan motor or clean and rehabilitate.

[maxnix]

A couple of posts on this in Infiniti Online Mechanic Forum.

Search on Darlington.

[coolman]

goody94q45, the fan is running about medium speed. If I turn on the defroster button, then the fan goes faster. When I change the fan speed, no fan speed changes occurs. Therefore, I think the fan stays on one speed. I get a different fan sound when enabling the defroster button.

Also, can someone provide me with a link to http://www.infinitipartsusa.com/ where I can find this part?

Thanks,
Modified by coolman at 10:29 PM 7/9/2006

[goody90q45]

Not all parts are listed at Joe's IOS site. Here's what you need:P/N 27761-85E01 Amplifier $76 (list) $57 (Joe)Prices are from Oct '05. They have increased a few %.