Heater Control: All or nothing

[NWA_Dave]

Sorry if this is answered in another thread, but if it is, I could not find it.

My heater temp control in my 2000 Limited does not work right. I am unable to adjust the temperature. Here's what I mean by that:
If the control is set to anything above "COLD", is as if it's cranked the whole way up to hot, so in effect I have two choices, either the lowest temp setting or the highest.

Does this sound like a vacuum issue, or something else?

Thanks!

 

[FrankieJoe14]

Its not a vac line. Its the solder/connections in the control unit that causes issues over time.

There is a member on here to rebuilds them for $59.

Here is the ebay listing - Toyota 4Runner 4 Runner Limited Climate Control Heat AC REPAIR 99 00 01 02 | eBay

And here is the post that you can reference.

http://www.toyota-4runner.org/3rd-gen-t4rs/210485-2001-2002-climate-control-unit.html#post2246254

 

[NWA_Dave]

Thanks. I contacted the guy on eBay, and asked his opinion. He said:

"You have other problems. Maybe heater control valve or service motors or dampers on the "box"

So, could it be vacuum line related after all?

Thanks.

 

[gamefreakgc]

Last I had a 4Runner apart with the electronic climate control, there are no vacuum lines. There are little servos (motors) on the sides of the heater behind the dash. To be honest, I have no idea how you'd get to them very easy though, I normally rip out the entire dash when dismantling and pull these doo-dads off last. What they do is rotate the air flow to come from the heater, or not. Sounds like yours only wants to be fully open or fully closed.

 

[Roamed YT]

It's the automatic climate control?

If so, unbolt the lower panel below the steering wheel. Check for the temperature sensor on the top right hand side (should be clipped on by the little vent in the panel).

If it is unplugged, plug it back in. When the temp sensor for automatic climate is unplugged the system will default to this condition. I had the identical issue when I bought my runner and traced it back to an unplugged temperature sensor.

 

[NWA_Dave]

Thanks for the responses, guys, I will check it out, and post updates here

 

[96RedRunner]

I just purchased a 01 Runner with same problem. The service manual has good info for troubleshooting this issue, page 752 for self diagnostic test. You can get the LCD display to tell you what sensor is causing the issue, If you press and hold the auto & recirc/fresh air buttons turn key to on position system will indicate a DTC code. 11 is for room temp sensor the one at drivers right knee, 21 is for photo eye on dash. I had a DTC code 11, removed panel under steering wheel, found room temp sensor unplugged. Thats my kind of fix = easy. Also check A/C System Repair section starting on page 1767. Good Luck

 

[NWA_Dave]

Awesome, thanks everyone! I won't have a chance to follow up until next week, thank you again!

 

[NWA_Dave]

Thanks, 96RedRunner! That was the problem!