Thread: HVAC / Dual Heat . Cold On Right Side

8 years with no HVAC issues. Last week I changed out the HVAC controller for a used one (my old one had 2 lights out).





All good until this morning; only have heat on the left side. After 20 minutes of driving, I feel a little bit of heat from the right side, but hardly what is coming out of the left side., and the air flow feels weak.

I guess I will but the old controller is and see what happens. Could be controller? Or blend door actuator? Could low freon cause this?

Thanks FordMan. Wouldn't you know it; I get in the car after work, and it is working just fine.

Originally Posted by wstefan20

Ah, the infamous intermittent failure problem....

If you're interested, I can fix your old head unit bulbs by replacing with either new bulbs or leds? You've helped me out with your write ups so I'm obliged to return the favor!

Thanks for the offer wstefan. I will keep this in mind.

Did some testing last night. The controller is the problem. When I lose heat on the right side, and wiggle the right heat slider, I get heat back. I haven't 100% confirmed, but it appears that as long as the heat slider is not all the way to the top, it works fine. Either way I've been in contact with the e-Bay seller, as they claim 90 day warranty on their parts.

I was chatting with the guy I bought this controller from on e-Bay. He was willing to take it back, and when I asked if he would give a discount for me to keep it, he have me half my money back. Sweet! Now I don't have to rush to find another one.

I also took apart my old controller, so will post pics of that (later) for future reference.

I've got one, from my ex 02.

My 99s have the auto head though (knobs not sliders) and the GTP just developed the same scenario, cold on the right. Brrr

Ended up replacing the controller 3 times; 1st (used) one had intermittent right heat, 2nd (new return) one had no power to the A/C button, 3rd (new) one worked like a hot damn. Gotta love when it takes 4 weeks to fix a problem that takes 15 minutes to do. Yay me. LOL

Mine ended up being a five minute fix... drop glovebox door, remove actuator, turn door to heat with pliers. Bam, done til summer when I turn it the other way. The door seemed to be stuck, though. Might work like it should if reassembled but it seems to regulate temp in the car just fine still. GP HVAC is a crazy mized up world.

I was hoping I had that problem; $45 and 10 minutes she'd have been fixed. This dual climate thing is silly..... left and heat control, but central fan control? Fail!

Back to this.....

Warmer weather, so now I want to use the dash vents and/or the A/C. I noticed the airflow was weak coming from the dash vents. After moving the selector around, it seams like defrost is ok, but as soon as I go to floor/defrost, floor or vent, I always have airflow coming from the dash vents. When I set the A/C to recycle, the airflow from the dash vents is weak. I had to put the fan on 3, where 1 or 2 is normally more than adequate.

I haven't looked at anything yet, but was wondering if anybody had experienced this? It's like the blend door is out of alignment/adjustment.

What I might do is swap in my old one, as the selector switch was working fine. See if it does the same thing.

Driving home last night, had the A/C on recirculate, and could smell the stinky diesel in front of me. Time to dig deeper.