Help: AC Heater Temperature Control Unit Upgrade (Manual to Auto)

I was bit frustrated with not having enough space for switch button, and needed to put switches for seat warmers I haven't wired up yet.
Found the AC Heater Temperature Control unit with seat warmer buttons on ebay,
immediately thought it will save me from having to add two pushbutton switches, and also HVAC Control from manual to automatic.
I was wrong to assume it would be plug and play replacement.
Old one (Manual Has Extra Plug in the middle)
New one (Auto Doesn't have the Extra Plug)
Please advise

 

That's pretty freaking wild. I would have thought that the ACC units would have more connections, not less.

Just spitballing, but the fan knob might be full current compared to just a mode selector?

 

There are more "missing" details to the Auto function...and the A33 on both version has other circuits to it. The wires in the drawing are just for the A/C circuit.

 

Thanks for the feedback. Considering hefty size of white plug, my un-educated guess says, it might be a relay built in in old module? Definitely Full Current!

Hypothetically, I can re-pin A33 plug with only 5 wires to see if it works but that will be a long shot. I would like to know how factory installed seat warmers are wired up.
I am inclined to take a part the old control module, but it's hot outside and I like my A/C.

Any takers?

 

Seat heater circuit also ONLY works with the Automatic A/C amplifier.

 

Hm, I thought all 3rd gens came with heated seats.

 

I read about A/C Amplifier blowing up all the time.
(I am not following why it is necessary?)
Seat warmers didn't come with it. When I put leather over over the seats, thought it would be a good opportunity to sandwich in heat pads when I put leather cover over factory clothes seats.

 

Seat temperature shares info with A/C amplifier for cab temp and other circuitry.

 

well, the plus side is i've been seeing and answering this question since 2014, when the scion fr-s/subaru brz was on the market with a similar automatic/manual hvac system. the really cool thing is that toyota tends to stick with what works.

the negative side is that this is fundamentally impossible with just the control panel. you would need to convert the entire under-dash components portion to the automatic hvac system as well, which is easiest with a donor vehicle to strip parts out of. it's possible, but not easy, or cheap.

 

Can you post a pic of your current switch panel? When I put heated seats in my truck I just bought a panel with more switch blanks and plopped in some switches. I'm like 99.9% sure you are lacking blend motors as well and replacing just the manual to auto panel is like half the battle.

 

Can’t say if fully true, but I had this discussion with my service advisor. I thought that auto would be better, but didn’t want a sunroof. We discussed the plausibility, but there are temperature sensors and dampers etc. that don’t exist in non premium system. The cost gets prohibitive and from his opinion (based on recalls and service issues) it was moving to a less reliable system.
I’m happy to follow along and live vicariously through you though.

 

Thank you so much for all the feedback I got.
I took over someone's lease with 4k Miles on it.
I didn't build the to my liking, tbh truck wasn't my thing.

Last five months I've amazed on utilitarian aspects of the truck and also how easy it is mod to anyone's liking. How they made everything so simple
1. Circular Rotating Vents are genius!!
2. Most panel trims just pop up!!!
3. Wow Push buttons, in 21 century!!!!
4. So much space in every crevices!!!!
(coming form having 4 V8 BMWs last 15 years)

About the prehistoric manual HVAC Panel,
if I turn the Temp control nob to the coldest setting, A/C and Closed Circulation buttons will engage automatically. It's pragmatic but super annoying what if I want the cold air without AC during chill enough day?

HVAC panel upgrade ain't just plug and play.
Temperature sensor and routing HVAC tubes might be necessary.
It'd be a long shot searching for 3rd gen donor vehicle with premium package.
I definitely think incorporating temp sensor to seat warmer is 'over-engineering'. Passengers turn on/off the warmer when their tootsies are too hot or too cold?! Even Germans don't do this!!

I am stuck with 110$ eBay part, I am gonna fart around if I could somehow make this work, keep you guys updated.
Thanks again

 

I am praying you forgot to update us. and when you see this reply you will come back with a solution!!

 

the manual version should be cable-actuated, where the digital version he's looking to upgrade to has actuators on all the vent direction flaps.

it's fundamentally impossible to not need to tear out the dash to install all the required parts.

 

Mine certainly doesn't. Not needed in Virginia weather, anyway.