I have a '90 Max and the heater/A/C blower motor runs on high continuously can not turn it off or use slower speed had to take the fuse out this morning. The car has climate control and I'm wondering if the "brain" in the dash went bad. Last week I put a new head unit in. Don't thing that had anything to do with it though. Anyone ever have this problem? Thanks.

Thats usually a bad temperature sensor ($20). Make sure you clean the connector as well. It usually has a good amount of corrosion on it.

Thanks for the quick reply. I'm not familiar with the temp. sensor. I do remember seeing a hollow tube going to a 1" square louvered like opening next to the control panel. Does this go to the sensor? Thanks

Depends which engine you have. For the VE engine, its located near cylinder #6, and it has a red connector!

Thanks for the reply eric. Checked the area you mentioned. I see a few connectors on the fire wall all around the heater control valve. I'm hoping you can be a little more specific in the location and appearance of the sensor. Does the sensor head go to the inside of the car?

Thanks Again,
Pat

You need to say which engine you have, DOHC (VE) or SOHC (VG). If you dont know which engine, then what is the year and model (se/gxe).

It's a 90 Max believe I got the VE. The car has the climate control not individual controls for heat and ac.

Thanks,
Pat

The following is for automatic climate control:
This should not be hard to diagnose. You have to locate 2 items and disconnect them. Both are located on the passenger side. Remove the glove box and the right side kick panel on the passenger’s foot area. The items you are looking for are the blower hi relay and the fan control amp. The relay is located behind the kick panel probably blue in color. There will be four wires connected to this relay. (black, green w/orange tracer, white w/ red tracer, and brown w/ black tracer). The fan control amp is behind the glove box with 3 wires to it. (gray w/blue, brown w/ black and black). Hopefully after disconnecting one of these will cause your blower motor to shut down. Replace the part that causes the blower to shut down when disconnected. If your blower continues to work after disconnecting these items then you have a short to ground and will be a little work to locate. Let me know how you do.

you have the -=VG SOHC=-

Thanks for the reply. Great information; sounds like you've had a similar problem.

Pat

Unfortunetly,I am not blessed with automatic air in my max, but I spent 5 years working on these cars.

Hey dsantos,
Finally got around to diagnosing the problem. In Balto. we've had 3-days of 100 deg. weather; need to get the AC going. I checked the blower amp first. Sure enough the blower stopped. After disconnecting the harness with the 3-wires you mentioned the fan control only operated the blower on high. Just ordered a new blower amp $80!! A strange looking device with a bunch of 1/8" X 2" cast metal tubes on the back; looks something like a heat sink. What the heck does this thing do?

Thanks again for the help,
Pat

Exactly that. It is a heat sink. I do beleive that portion will be inserted into the evaperator box. When you pull the old one out, you will see the same thing.