FAQ: Warm/Hot Air on Drivers Side, Cold on Passenger Side

Here is another link that shows how to add r134a to your car. It is part of the compressor write up. https://rivperformance.editboard.com/t6120p45-write-up-ac-compressor-clutch-replacement

AA wrote:

Cool beans. You may also find this link handy (I'll post a copy on page one of this thread for future ref):

https://rivperformance.editboard.com/t2500-write-up-hvac-assembly#27279

Thanks again, homey. This is what i'll be targeting.

Hi guys my ac works on the passenger side, but driver side and center arm wrest doesnt blow cold, just heat, any ideas?

bmcd9179 wrote:

Hi guys my ac works on the passenger side, but driver side and center arm wrest doesnt blow cold, just heat, any ideas?

Possibly low on refrigerant. That has solved that problem for others here.

Otherwise there could be an issue with the blend door actuators - does it blow hot and ambient, but not cold? If so, it's probably low on refrigerant. Don't blindly add a can though - make sure you get the high and low side pressures checked first.

bmcd9179 wrote:

Hi guys my ac works on the passenger side, but driver side and center arm wrest doesnt blow cold, just heat, any ideas?

Possibly your blend door actuator. I had the EXACT same symptoms as you.

That's what my problem was. I replaced the actuator and BINGO. Got my cold air back.

After an exceedingly long time of running without driver side actuators, I decided to go ahead and replace the defective parts so I'd have heat this winter without needing to crawl under the dash to change the temperature. I purchased two new Dorman actuators after double checking part numbers.

Everything works great other than being completely in reverse. Full heat makes cold air come out, full cold makes heat come out. Setting the control to "floor" causes the middle vents to activate. Changing it to middle makes it go out to floor.

I've tried pulling the battery terminal and letting it reset. It goes through the 'calibration' for about two minutes. Then everything comes out normal on passenger side, but reversed on driver side.

At this point I'm at a loss to figure this out. The actuators plug in one way and connect one way. I don't see any way that I could have reversed everything. Other than having to set it backward (ran it at 90*F for full cold) it fixed my issue.

Another actuator I just replaced on my Fleetwood worked perfect out of the box. Swapping it with the one from the Riv (604-106) worked fine as well. When in the Caddy, the actuators behaved and calibration went along just fine. No issues appeared. When in the Riv it would just operate backward after calibrating.

If anyone has any ideas I'd really appreciate it. I'm probably overlooking something stupid. LOL

Alright. Figured out the issue and it was quite stupid. I had to open up the actuators to figure out how I'd crossed everything up.

The Riv uses Dorman 604-111 and 604-106. Problem is that the lower two actuators on the driver's side (Vent control and temp control) use 604-111. The reference guide I used specified 604-106. Externally both actuators are the same. Internally they are very different.

Dorman 604-111 seems to have an additional variable resistor in it that allows it to 'fine tune', whereas 604-106 is a less sophisticated unit and just moves between preset destination as near as I can tell. I didn't realize this difference until I compared both units. My computer was essentially trying to calibrate and getting all sorts of mixed up signals because it expected one part and had the other. I swapped the ones I had for the passenger side (again, backward part listing) with the ones that I thought went on the driver's side and everything worked perfect.

The main failure of the original actuators was that the main control gear was a two piece unit. It's a plastic/nylon wheel with a metal slotted rod driven through it. Over time the metal either cracks the wheel or grinds it loose with usage. This results in noisy grinding as the part breaks down.

Relatively speaking, the actuator is fairly robust other than the faulty gear design. The only main difference going from the original unit to the new type unit is that the Dorman gear design is all in one piece of plastic. It also has spokes around the rim to further reinforce it so that it shouldn't crack under any amount of conventional use. I believe this is why the new units tend to be reported as more reliable.

End result? We pay $100 (depending on where you get it) for a $0.50 cent cracked gear.

It's good to have heat again!

Nice find. Glad you got it working properly!

This is the two part gear design with a crack in progress. Finally found where I tossed the old actuators so I could snap a pic.

Natesriv wrote:

The yellow arrow is the gear which connects the motor gearing to the metal wheel (the white arrow). The red arrow shows a blue gear which I believe tells the PCM how many revolutions that actuator has turned... This revolution count MIGHT be the reason the actuator doesn't move the full range.

Thanks for the picture. I aligned my blue gear up like your picture shows and it works now like it should.

I have researched till I am blue in the face, HELP!!! I see there are 3 actuators on the drivers side the top and lower appear to move as I make changes, the middle actuator does not. How much are they supposed to move? Any help will be appreciated, Thanks

I lent my sister the car and it came back with no heat on the passenger side. We need heat for 2 weeks a year so I dropped the glove box and pulled the actuator. Operated the temperature controls with the actuator off the white post and it did not move. I opened it up and exercised the piece that moves the white rod when activated, it had moved so that it was not quite flush with the outside actuator case. Pushed it all the way in and all is good, winter is probably over since it will get to 70 today but it felt good to fix it.