Hi all,

My 99 SR5 has problems when it comes to the A/C and heater. It does not have the auto climate control. I've done a number of searches for these symptoms but can't quite pin it down.

The truck only has 117,000 miles on it. The A/C worked periodically for the first year I owned it (last year), then stopped blowing cold altogether. The heat blows HOT regardless of the setting on the temperature wheel, and regardless of whether the switch is set to recirculate or bring in outside air. Even when I turn the blower setting to off, it is slightly blowing hot air at me. The air outside can be freezing, and the air coming through the vents is still hot.

The truck does not overheat and runs fine otherwise. Any ideas?

 

Assuming two separate problems...
Can you hear the blend door moving/ feel resistance when you switch the temp? Above the blower motor, passenger side, below the glove box and close to the door, requires a torx bit.

When my a/c did that on the 96 it was the expansion valve, was holding its charge fine and a pressure check indicated where to start. That's in the black box just above the passenger floorboard. Not saying either are your problem, just giving you a starting point.
Even some pics...
Post 262, 266
https://www.yotatech.com/forums/f200...1/index11.html
Posts 687-690
https://www.yotatech.com/forums/f200...1/index28.html

 

Thanks for the links. Wouldn't that be something if it was as simple as one or both of those doors malfunctioning? It seems to me that there is resistance when turning the dial, but I'll see about ruling that out at least.

Habanero, when your 96 had issues with the AC, would it blow fresh air at the outside temp?

 

IF I remember correctly- I didn't have blend door issues so it would blow fresh if I had it on fresh, not if I had it on recirc. The a/c would stop working, then start again, then stop. After a bit it just plain stopped. The link tells the rest. I capped off the system where I had it apart to keep moisture out and replaced the receiver dryer when I put it back together. Getting to the evap was a little bit of a puzzle but I like puzzles.
Pulling the blower motor is easy enough and there's the door right there to operate the switch and watch. Even pulling the trim panel to get to the switch is possible if you don't find anything at the door. The expansion block's a bit more work.

Just giving you a point A, it's up to you to find B, C and possibly, D.