Inner and Outer Temperature Display do not work on startup. Please help me diagnose.
 

When I start up my 2005 Acura RL, the outer temperature display in the instrument console, and the upper temperature display for the climate control do not light up. Then, after driving for a period of time, they magically come on. When the upper temperature display is not on, I cannot use the A/C. this SUCKS in the summer. Once in a blue moon, both displays work when I start up the car. But, for the most part, I have to drive for 15-30 minutes until the temperature displays decide to turn on. The battery is working fine and I checked all the fuses in the driver's side fuse box. I am nonplussed as to what to do. I'm hoping it is an easy fix like a fault relay or switch. Where should I start to diagnose?

Sounds like you got some loose connections in the back. I'd start there.

loose connections in the back? What do you mean the back?

I found my weekend project! Going to reflow the board Saturday morning and see if it fixes the problem. I am somewhat skeptical that it will but it's worth a try, not like I have anything better to do.

I was expecting to see poor soldering joins but these look fine to me


https://cimg4.ibsrv.net/gimg/acurazi...8b6314f2df.jpg

I am going to resolder it today because maybe some joints are cracked and dry, I can't tell just looking at it. Today I drove the car though and the outside temperature display was not showing. This leads me to think that this is not an issue with the electrical in the upper display. I would like to test components in the B-CAN system where both the outside temperature in the multi-information display and the inside temperature in the upper display are members, but I don't have diagrams.

Yep, this did not fix the problem. It is not poor solder joints on the dash information display.

Ouch, I honestly thought it would be that...