Heater Control Simplification

[roastin300]

I am over all the leaking and barely functioning auto climate control. I have been wanting to convert to the manual climate control for a while now, but am kind of wanting to remove the majority of it all and throw a single switch in to make it on or off. Maybe direct it all to the front windsheild or distribute it to the windsheild a couple of the head vents.

Anyone done something like this? The ducting is straight forward but I am not familiar with how the electronics of the heater controls work. Obviously send power to the blower fan, but is there additional power that needs to go to some sort of valve that allows engine coolant to enter the heater core or not?

I will start rippin into the the dash here in a few weeks and lookin at wiring diagrams...

[system6]

I "disconnected" the vacuum supply to mine the last time I pulled the motor and now it blows out the defroster automatically so if you just wire the fan on the relay and manually swithced the relay then you would have the fan control. I don't see any reason that you can't put an old school cable (or even an under hood manual) valve in the hose by the firewall. That would be simple. I just bypassed the heater core all together on mine; I figure if it isn't t-top nice outside the z doesn't need to go outside sooo...

[Careless]

roastin300 wrote: Anyone done something like this? The ducting is straight forward but I am not familiar with how the electronics of the heater controls work. Obviously send power to the blower fan, but is there additional power that needs to go to some sort of valve that allows engine coolant to enter the heater core or not?

doesn't the water rooster on the firewall have two wires going to it?

[roastin300]

[quote]Careless wrote:

Anyone done something like this? The ducting is straight forward but I am not familiar with how the electronics of the heater controls work. Obviously send power to the blower fan, but is there additional power that needs to go to some sort of valve that allows engine coolant to enter the heater core or not?
doesn't the water rooster on the firewall have two wires going to it?

Yes. This is partial to my question. I am not sure if there are other items like this that will or will not need to be switched. I will come up with something simplified that will free up space under the dash, remove some weight, and work better than the current crap OEM setup.

[roastin300]

And the process begins tonight...

[adamvann3]

Mike G

Benedict and Taylor

Benedict's build thread pg 10&11: viewtopic.php?f=13&t=6371&start=162

[Rick88ss]

Remember you need A/C to defrost your windshield.

I know you need the heater there in Colorado.

The only thing the heater needs to work is the water cock valve thing by the firewall. When vacuum is applied to it the valve is closed and the hot water doesn't circulate through the heater core. When the vacuum is taken off of the valve it opens letting the hot water circulate through the heater core. You can easily hook up one of the useless solenoids to do this job. EGR solenoid,Fuel pressure solenoid will work and I'm sure you removed them a long time ago.
Of course the blower has to work to blow the air out of the vents.

All the vents need is vacuum on the vacuum line that goes through the firewall. Just put a check valve inline.

Since your climate control is electronic I don't really know if other sensors need to work in conjuction with the controls.
Will a manual A/C dash control work in your car to only control the heater and vents?

[roastin300]

I have it all gutted and the original plan was to just run coolant through the heater core at all times. I also thought about doing literally exactly what you said. Ditch the vacuum tank up front, put a vacuum line off the manifold to a 2 port solenoid (the stock one I yanked years ago and still have) and a small check valve so it does not see boost...not like it matters, it will just close the valve under boost anyways....and a switch to open and close it. The advantages I see to this is being able to heat the engine up faster, if there is ever a leak in the heater core, I can switch it off, and I can move hot or ambient air through the vehicle. I will most likely do this. I am also wiring a solenoid and pulling 14V right off the battery directly to the fan blower motor. The heater core is exactly the same size as the fan blower outlet so it will be fastened directly to the fan motor. After I relocate this and plumb the coolant lines to it, which shouldn't be too hard, I am plumbing a single duct to the vent that services the windshield and the little vents on the drivers and passengers side by the windows, because these are a part of the defrost main vent tube. EVERYTHING else has been ripped out including that huge white air flapper box and the AC evaporator and its box. I will have a total weight saving of about 34lbs by going this route, the heater will be much more effective than that dumb auto climate control, and my wiring is significantly cleaner under the dash now. I think its well worth it.

[Rick88ss]

I wouldn't leave it circulating hot coolant all the time. When you use you're Z in the summer time it's gonna be hot as hell in the car.
You can remove the vacuum canister and vacuum pump too.

[roastin300]

Your very right Mr. Rick. I will throw a solenoid control with a switch to send vacuum to that valve on the firewall.

What do you guys think about these units? I would rather not spend the money but its a simple compact unit that I feel would be more reliable and exchange more heat than the stock blower motor/heater core setup. I don't know what the stock blower motor flow rate is or the heat exchange rate of the stock heater core. Relatively speaking, these 2 units seem to have decent flow and heat exchange.

http://cgi.ebay.com/ebaymotors/Summi...item564602c47d

http://cgi.ebay.com/ebaymotors/Summi...item56464689cb

[roastin300]

Or go even bigger:

http://cgi.ebay.com/ebaymotors/Summi...item5ae2b6e2d1

[roastin300]

So far I am at a 48lb weight reduction of mostly crap under the dash. This reduction does not include the fan blower motor or the heater core. I am retaining that. I am fabbin a TIG welded aluminum heater core housing and mount setup with a single outlet feeding the defrost vent only. Blower Motor control is in the process and trying to decide which route I want to go.

I removed 2 plug in modules from inside the spare tire well. They seem to have not effected anything on the vehicle that I still have. Anyone know that these are? I removed the vacuum canister and pump as well as all the vacuum lines. I also think the big relay box on the passenger fender under the hood can be removed because all I need is the horn relay I believe. I don't have fog lights, AC, theft system, headlamp washers....nothing.

[-Strike-]

I ripped everything heater related out of the 84' for the future project. Not worried about having heat or a blower at all, the car is going to be a special occasion type anyways when the time comes. The Shiro remains the summer driver, both get garaged when the cold weather comes in.

Only wires I left for the front end were the lights and horn. And of course the new engine harness once the motor is done.

[Rick88ss]

50 lbs isn't going to make a big difference. I kinda did the same thing but I left the a/c evaporator and removed the heater core. I disconnected the heater door solenoid and screwed it shut.
I woulda just removed the evaporator and vacuum tank and pump.
Also remember that for defrost to work correctly you need the a/c to work too. When you select defrost the a/c compressor engages and works along with the heater to remove the humidity in the cabin. The heat feels better on your feet and face also. LOL

[roastin300]

Not too worried about comfort rather than just being to keep the windsheild clear and heat the car up inside a little bit in general. I don't have AC, never have and never will. When I say defrost, I mean blow hot air at the windsheild and melt the ice. I am not using the heater control display so I am not describing hitting the "defrost" button. I will be using simple switches to control it. I think the stock system is over the top complex for how well it worked....or rather lack of how well it worked. I don't need all that shit....so I ripped it out.