Another EATC automatic climate control gremlin; only turns on sometimes and it depends on weather

[ExplorerLouis]

Hi all, I'm new here but have been digging for info for months! Late fall last year I bought a 97 limited, 5.0 AWD, and it has all the nice electronics the 90s had to offer... long story short, my EATC (automatic climate control) acted wonky all winter, only coming on when I first started the truck. Turn they key off, pump gas, turn key on...no EATC. Buttons lit up, but no screen. Now spring is here, and the EATC is coming on every time...but it no matter how many times I try it always resorts to reading in Celsius.
Anybody dealt with a wacky fuse, janky solder joint, or something that would explain why it's acted like this? Much obliged!

 

[J_C]

Considering the age of the vehicle, yes, could be something like fouled fuse contacts, frayed or shorting out wire, head unit board has a fault, etc.

I'd pull the head unit out of the dash and see if it's getting power on the main power feed, not the interior lighting feed. If not, backtrace towards the fuse box. If power is getting to it, probably a fault internal to the head unit, open it up and see what you can see, especially things like burst capacitors and broken solder joints.

 

[ExplorerLouis]

Considering the age of the vehicle, yes, could be something like fouled fuse contacts, frayed or shorting out wire, head unit board has a fault, etc.

I'd pull the head unit out of the dash and see if it's getting power on the main power feed, not the interior lighting feed. If not, backtrace towards the fuse box. If power is getting to it, probably a fault internal to the head unit, open it up and see what you can see, especially things like burst capacitors and broken solder joints.

I appreciate the input! Did some tracing to back of head unit and fuses back when it was cold and nothing was off then. I'll hafta see if a buddy who knows circuit boards can lend a hand after pulling the unit.