A/C display is acting very strange...

[Fester]

Hello, I was hoping someone might have an idea on what is currently plaguing my 1999 4Runner. When I turn the ignition, sometimes the dislay for the A/C acts strange and will display garbage, count from 0 to 10, while graduLly increasing the fan speed, all the while not allowing for proper operation of the A/C. If i turn the engine off and turn the key to restart engine repeatadly, it sometimes will resume normal functions. My father said something about an A/C head unit or a head unit of some kind that might be bad or going bad... Any ideas or suggestions? I guess I should add that all other electrical functions appear to work correctly even when this problem arises... Thanks

 

[TheDurk]

The digital unit has a self-diagnostic that reads out on the temp display. Get the instructions and codes in the online FSM towards the end of the Diagnostics section. No scanner needed, just push buttons.
http://www.ncttora.com/fsm/1996/SIL/fsm/repair.html

 

[Fester]

The digital unit has a self-diagnostic that reads out on the temp display. Get the instructions and codes in the online FSM towards the end of the Diagnostics section. No scanner needed, just push buttons.
http://www.ncttora.com/fsm/1996/SIL/fsm/repair.html

Thanks for the reply. I went ahead and tried the test method about 10 minutes ago and only got code 21, but the manual says that that code is probably because I chose to do the test in the dark. Whats interesting is that when the problem occurs, I cant even access the test mode. The entire area of the temperature display has every LED lit up. Have to keep turning the key on and off and after enough tries, it finally allows for proper operation of the A/C... very frustrating...

 

[rjaudi]

I think most of the time those climate control units need to be rebuilt. I believe some people do it for 150.

 

[Fester]

Thanks for the reply. After a little digging and the right combination of keywords, I was able to find a repair service for $150 on eBay and I found another service offering to do the work for $200 using a Google search. I guess I will run the diagnostics again tomorrow and then pull the unit out and check the connections, as many have suggested in previous threads related to problems encountered with the digital climate control unit.