9000 interior fan wont shut off

If the fan is always running at high speed, it isn't the ACC unit. This is the failure mode of the fan speed controller - a separate part that is near the air intake behind the false bulkhead (under the hood, right side). The fan speed controller costs about US$150 vs. about US$700 for the ACC unit.

Walt Kienzle

1991 9000T

You're right on the diagnosis. But I think the fan speed controller can be had new for about half of the price you quoted. As for the ACC, it is expensive. But I never had one died on me. I'd as soon get one from Ebay if it does. The price is unbelievable.

Thanks for the info. I am checking some places around the net and should hopefully find a cheap one soon. Was this unit basically installed in most of the 9000s with the ACC? Or do I have to look for just specific years/models when calling junkyards?

Walt Kienzle wrote:

After seeing a previous post saying that the fan speed controller should be about half the US$150 cost I estimated, I decided to check

to see what is offered. Apparently there are two types of controllers. 86 - 91 model years use part # 9629106 and sells for US$128.80. 92 - 98 model years use part # 4632477 that sells for US$104.00. I thought both units were electrically interchangeable, but the newer model has a larger heat sink that may not physically fit in the older models.

Walt