1990 Corolla AC Fan control switch is broken.

[Acies]

So I bought this car a couple weeks ago. At the time the switch only moved between high and off. Over the last few days it has started to occasionally switch between the two settings as i went over bumps or the car was jolted. Now it won't function as all. So what I need first is to figure out how to get into the AC system so I can hopefully fix the problem. If anyone has any advice about what I should do once I get in there that would be appreciated too.

Thanks!

[90 GP]

Can you place switch in each of the four settings? If so it isn't likely the switch but the blower resistor which sits inside blower housing. Look up under dash in area by glovebox . There is one screw holding resistor into housing with a wiring harness plug attached to it.

[Acies]

It didn't fit into the settings properly. The switch could travel the full range, but it was kind of springy and moved back to the middle when released.

I checked the blower resistor anyway(assuming I found the right thing), and it looked alright. 3 wire coils on the part I removed? I'm not sure what it was supposed to look like, but it wasn't obviously wrong in any way.

I took off the plastic covering over the area around the AC, and removed the little storage box below it as well. With that removed I can see that it has been modified before, the switch was held in place with a zip-tie. I can't see exactly what it going on inside yet, though.

I haven't been able to remove the cover for the AC itself (the plastic with the labels for the switch settings and such), I think I'd need to figure out how to remove the knobs on the switches. I also haven't been able to get the whole unit out of the area (given the way the rest of the switches seem set up this might be impossible?) Do you have any idea how I might do either of those to get a look at it?

[REN69]

it's probably the wires then... the system is got an actual wire that goes out through the firewall and into the engine bay, have someone move it for you while you look under the hood and you will see what I mean.

[90 GP]

Sounds like somebody tore apart the original switch which explains why it won't stay in one setting. You need to replace the switch.If you have a NAPA nearby they show one for a Geo Prizm which should be identical. Another possibility is to check out a junkyard for part. Check out a Mitchells or other service manual for specifics on how to get panel off to replace it. On mine you remove trim panel around heater/radio and then remove four screws which hold climate control panel in place. Here is link on switch.

http://www.napaonline.com/Search/Det...+50029+2029014

[retiredat44]

Originally Posted by 90 GP

Sounds like somebody tore apart the original switch which explains why it won't stay in one setting. You need to replace the switch.If you have a NAPA nearby they show one for a Geo Prizm which should be identical. Another possibility is to check out a junkyard for part. Check out a Mitchells or other service manual for specifics on how to get panel off to replace it. On mine you remove trim panel around heater/radio and then remove four screws which hold climate control panel in place. Here is link on switch.

http://www.napaonline.com/Search/Det...+50029+2029014

that's good info.. our switch is a bit flaky and the fan speed only works on 3 out of 4 settings..

but $60.00 is a bit pricey!

[Acies]

Originally Posted by 90 GP

Sounds like somebody tore apart the original switch which explains why it won't stay in one setting. You need to replace the switch.If you have a NAPA nearby they show one for a Geo Prizm which should be identical. Another possibility is to check out a junkyard for part. Check out a Mitchells or other service manual for specifics on how to get panel off to replace it. On mine you remove trim panel around heater/radio and then remove four screws which hold climate control panel in place. Here is link on switch.

http://www.napaonline.com/Search/Det...+50029+2029014

First of all, thanks. I would have gotten back to this thread sooner, but my internet has been having some trouble. Second I should have another switch soon, but I'm having some difficulty getting behind the panel. I think I have the same setup as you described because I take off the trim and 4 screws, then I can detatch the panels with the labels on it. However there's a secondary panel behind that, with the light on it, and that seems to be attached to all of the cables back there as well. I detatched the water valve cable, which has helped things a bit, but it feels like there is something else that is keeping it from coming out. Any idea where it might be and how to get to it?

And sorry for all the questions, I've researched this a fair bit but I haven't found any detailed guides for this.

[bcp477]

I had EXACTLY the same problem in my AE92 when I got it (also, a few weeks ago). The switch is definitely the culprit - when mine broke for the previous owner, whenever that was, it shorted out and has a nice burn mark on the underside. This is apparently a common problem with these switches. I couldn't easily locate an identical switch in my area (though I did not check with the Toyota dealer....as I had some idea that the price might be a bit high)......so I just re-wired the switch circuit with a generic multi-position switch. Works just fine.

As for getting the HVAC panel out......if you haven't done so already, you'll need to remove the face of the vertical part of the console. Otherwise, the HVAC panel will never come out. In order to do that, you've got to pull screws from the sides of the console, down low, as well as remove the pieces right around that area on the dash.....and everything inside that vertical piece, such as the radio/ storage "box", ashtray, etc. It's been some time since I did this....and it is hard to describe. But, the key to getting the HVAC control panel to come free is that piece on the front of the vertcal portion of the console.