Electronic climate control issues (fan problems)

Ok,since I am a valued employee at Johnson controls, and test HUGE air conditioning units, I happened to get a few pounds of R-12 and evacuate my A/C system, put a good vacuum on it. A/C blows GREAT (about 42 degrees), BUT the problem is this:

The climate contorl either works or it doesn't. It is a digital (91) that you set the temp and it look like this:

Auto--Low------------------High

the problem is the fan does not turn on AT ALL on any settings (A/C. vent heat, etc), UNLESS its the whole way to the right (at the high setting). Auto does nothing, and on low to right before it goes the whole way to the right, does nothing.... My question is do I have a bad climate control unit? Does anyone have a wiring diagram for this???

Also, anyone have one for sale at not an outrageous price (and a speedometer as well - lol) THANKS!!!

Mine does same

Mine does the same thing, before replacing anything try this. I found my problem to be the wiring pulg that goes into the blower control module behind the glove box has a loose fitting on the connector.

When I smack the glove box pretty hard or reach behind it and wiggle those wires going to the blower controller, it works fine, or until I hit a bump.
To fix it I pinched the connectors just enough to make a good tight contact on the connector and it works just fine now, bumps or not.

Just a thought!

awesome - I went through all the trouble taking it out and looking at the connections and testing the transistor, and it was fine - put it back in, and it was just a loose connection! YAY! MY heat/ AC and fan all work - I feel like I am living in luxury

anyone have a wiring diagram for the blower control mudule??? because it is not working properly again, and it doesn't seem to be a loose connection - maybe the relay is bad...

need more help!

so no wiring diagrams anyone??? I was wrong - my dad checked the whole part out, and it is fine. what else could be causing the fan/blower to only work on high and not any other setting ARRGH - always something with this car..

If your blower only works on High, you probably need a new blower control module. Part No. is F7SZ-19E624-BB. It requires a new connector to be spliced in (no big deal). It's not cheap though, around $150. Module has been re-designed with a larger heatsink.

thats why I was hoping for a wiring diagram - my father is an electrical engineer, and he took it all apart, and looked at the relay/transistor, other parts on the circuit board, and tested them, and said it was ok... I dunno arrgh...

bump

any ideas here?

If you're in a hurry go to the library and get a wiring diagram. Or sign up for http://www.alldatadiy.com for your car and get the pinpoint tests and wiring diagrams from there.

You'll find that the climate control system has a self test mode that can check for problems and tell you what they are.

1. Turn ignition switch to ON position.
2. Depress FLOOR button on control assembly.
3. Slide blower switch to HI.
4. Push both COOL and WARM buttons simultaneously for three seconds until appears in the control assembly window.
5. After about 20 seconds, the "-" symbol will be replaced by a code. Refer to the Error Code Key to identify the error.
6. If 75°F or 24°C appears, power to the vehicle has been interrupted. Repeat Steps 1 through 4 above.
7. To exit the diagnostics function at any time, turn ignition switch to OFF position or depress the OFF button on the control assembly. When the control assembly is turned back on, the temperature door will self-calibrate for 20 seconds.

Click to expand...

There a bunch of tests for the climate control system documented in the alldata notes including tests for the blower motor, and the blower motor control.

I didn't know you could get a wiring diagram from the liabry - what do I search there for? I don't think the librarian would know what to tell me if I told them I needed a wiring diagram for a 91 thunderbird supercoupe, but maybe I am wrong... I may just buy another blower control module, but my father said he tested everything on the board, and it looked good to him... ugh

The library has books. Some of those books (in the reference section) will be Chiltons, or Haynes, or similar auto repair manuals. you can make copies of the necessary pages from them. Some libraries also subscribe to www.Alldata.com to allow library patrons access to the online data. (cheaper for the library than to stay on top of all the reference books)

If you have a decent ford dealer service department, they may even let you look at the Ford books for it, if they have them.

Talk with your dad... he can help you figure it out. The fan is fully controlled by the control module.