heat backdate and climate control slider delete question

[TastyReuben]

So I've done some reading and cant find much intel on this. Basically I want to backdate the heat in my '83SC, deleting the engine compartment aux blower - plenty of info on this, seems easy. But I also would like to delete the climate control slider box from the dash - its ugly and I want a blank dash and simplified controls.

I believe this would mean deleting the entire damper box and possibly footwell blowers from the frunk, also losing fresh air in which is fine.

questions:
-Can I just wire the footwell blower to an on/off switch? or maybe a 3 speed?
-Can I route air from the left flapper box directly to the defrost, and then go directly from the right flapper box to dashboard vents? leaving control of the two functions entirely to the flapper box control levers? Has anyone done this?
-Concerns?

I live in SC so I only need heat maybe 3 weeks a year, So am mostly aiming to retain some defrost function.

TIA

[SpyderMike]

I removed mine in my 1985. I live in OC. I removed the footwell blowers and ran both to the defrosts. I get plenty of heat.

You could keep the footwell and wire to a switch.

You could also do exactly as you are suggesting and split the two sides to different functions. I, personally, don't see any concerns...

[turbine930]

[QUOTE=SpyderMike;12314199]

You could keep the footwell and wire to a switch.



I‘ve done that and it works perfect!

[turbine930]

[TastyReuben]

thank you, seems like maybe some brain power needs to be applied to wiring in some sort of switch / relay and maybe 3 speed switch for footwell blowers? But Spyder you say you get enough heat to defrosters without, have you also deleted the blower in the engine bay?

Can you guys post pics of your frunks and routing?

Here's what id like to move towards, only pic I've found so far:

[SpyderMike]

Yes, I deleted my engine compartment blower. My hose routing looks just like that pictured. It is easy and quick mod. I would say "try it first". If you don't like it, it is easy to change

[SpyderMike]

This photo is a bit cluttered, but you can get the idea of the hose routing.

[EC900]

I think once you remove both the distribution mixers (and sliders) and center fresh air blower, then routing some flex hose with be easier to imagine.

You lose the ability to to control the air flow mechanically, but since you want one side to direct heat to defrost and dash vents while the other just to the foot well, using the heat flap levers basically solves the problem. With the aid of footwell blowers as-is, the performance will be determined by your needs.

One thing you might need is a splitter to direct (one side) heat simultaneously to mid-dash and defrost vents. Your foot blowers being so close to where they’ll be directed, a variable speed fan switch may not even be needed.

Certainly it’s a clean look and simplifies the system.

Even in midwest winter, I rarely use full heat with levers up or get to the point defrost or window fogging is a problem with the aid of just the fresh air blower and with not having footwell blowers at all.

(For me) trying to comprehend the electronics of relays, resistors and 3 separate speed fan switches for the footwell blowers will take some expertise, here’s a link where someone tries to use an oem 3 speed fan switch -

How to Install footwell blowers in pre -84 911's

[SpyderMike]

You can use a simple PWM motor controller. Easy and inexpensive way to be able to dial in the blower fan to any speed. I use them for the Evap Blower and a Condenser fan.

[TastyReuben]

Originally Posted by SpyderMike

This photo is a bit cluttered, but you can get the idea of the hose routing.

Thanks. Yeah that looks much better than stock. What is the black flex tubing to/from? looks like you have a plastic reduction piece of some sort as well.

I think I'm gonna go for the simplest system possible and delete almost everything, if i'm lacking air flow ill look to add an in line ducted fan with 3 speed already built in.

Also I see your drip line there, what did you use for a blank off plate for the fresh air intake vent?

[SpyderMike]

The larger black tubing heads to the dash center vent. The smaller black ducting is headed to the driver's side vent. The plastic piece is stock...usually buried beneath all the mixing/distribution ducting you will be removing. I have retained AC, so the black ducting is moving cold air. The black plastic piece has four outlets...two directly to the interior (below the trunk floor, and the two you see here.. I will post pics of my fresh air vents solution and one attempt for pushing fresh air (prior to my AC install).

[SpyderMike]

This is a stock setup ..

[SpyderMike]

Post 289 here shows my attempt at a fresh air supply (pre hybrid AC system install):

https://forums.pelicanparts.com/porsche-911-technical-forum/819396-so-how-backdate-project-starts-15.html

[SpyderMike]

Here is my fresh air vents solution...simple ABS parts...top post here:


https://forums.pelicanparts.com/porsche-911-technical-forum/819396-so-how-backdate-project-starts-10.html

[TastyReuben]

That's the diagram I needed, thanks. Yeah ill be retaining factory style AC, with Griffiths parts.

I was hoping there would be some kind of pre made block off plate for the fresh air intake vent, but your solution seems easy enough.