AC/Heater That will fit

[Brett Proctor]

Well guys I think I hit the mother lode

Went to the yard and pulled that 1992 Mercedes 600 SEL V12 AC/heater unit

All measurements show that it will fit on top of the center tunnel under the dash and not interfere with the pedal assembly.

It was a pain to get out but I managed with only one small accident to the plastic case.

Controls are very simple also. On top of that you can control left and right temperatures in the car separately

This is a pre 2000 unit, after 2000 I don't know if the plumbing is the same. There is High and Low pressure side for the AC and 3 lines for the heater. Not sure what the third line is. Looks like a bypass.

If you don't have a water cooled engine then just omit the heater part

I'll quit talking and post the pictures

 

[ratrog64]

Is it the Heat and AC for the rear passenger compartment only? A separate unit for the front?

Looks like it will be a nice fit!

 

[Brett Proctor]

This unit is located in the center console of the car. It supplies the AC/Heat to the back of the car.

The square footage in the back of this car is probably close to that of the sterling's interior.

I have it apart right now, cleaning all the parts and replacing seals so I'll get some photos of it and post that.

 

[islandman]

I'm assuming the flaps are valves for heat are using actuators based on the number of wires and switch design. Given the year its pre-body computer etc.. So I guess the next step is track down the wiring diagram.

It will be pretty neat to have a Sterling with separate passenger and driver heat controls!

*thumbs up*

 

[Brett Proctor]

I'm assuming the flaps are valves for heat are using actuators based on the number of wires and switch design. Given the year its pre-body computer etc.. So I guess the next step is track down the wiring diagram.

It will be pretty neat to have a Sterling with separate passenger and driver heat controls!

*thumbs up*

Flaps are manually operated. No actuators

The flaps direct the air out the top or bottom openings

I found a FSM for the car with the wiring diagrams in it but because of its format and the age of my operating system I'm having trouble with it. Size of the file is 1.3GB.

 

[Brett Proctor]

I'm assuming the flaps are valves for heat are using actuators based on the number of wires and switch design. Given the year its pre-body computer etc.. So I guess the next step is track down the wiring diagram.

It will be pretty neat to have a Sterling with separate passenger and driver heat controls!

*thumbs up*

Flaps are manually operated. No actuators

The flaps direct the air out the top or bottom openings

I found a FSM for the car with the wiring diagrams in it but because of its format and the age of my operating system I'm having trouble with it. Size of the file is 1.3GB.

 

[islandman]

Flaps are manually operated. No actuators

The flaps direct the air out the top or bottom openings

I found a FSM for the car with the wiring diagrams in it but because of its format and the age of my operating system I'm having trouble with it. Size of the file is 1.3GB.

PM me the link, I will see if I download it for you

 

[Brett Proctor]

I'm thinking that I could use that other blower motor that I posted http://www.sterlingkitcars.com/memb...ning/1722-compact-blower-motor.html#post19554

for recirculation of the interior air and/or circulation of the exterior air into the cabin.

That way I wouldn't be asking to much from the system to do it all.

Still haven't run tests on how much air the blower puts out, but for a system that is virtually a bolt in option I'm not going to complain if it doesn't put out air like a factory oem system.

One thing to point out is the blower motors look to be interchangeable and the fans have a different blade pattern but thew fans seem to be the same size, so you may be able to switch them around.
The only thing I see at this time is the blower for the "02" looks to have only 2 speeds where as the "92" blower looks to have 3 speeds, But this is just guessing at this point in time.

When I went through the system I took note that the heater core and evaporator sit over each other, so if used for just for AC you could remove the heat extractor and gain more circulation of the air since it isn't having to go through the heat extractor.

 

[Peter]

That is a great unit, very compact and it would fit between the front bulkhead and the old gearshift position behind the console, all I need would be HEAT from somewhere and a AC system.*nothing to see*

 

[Brett Proctor]

OK had some time today to look through the manual.

Found out how the right and left temperature system works.

There is a valve that regulates the flow of coolant through the heater core/exchanger

I may go back and get this before they recycle the car but if you wanted to omit this feature all you would have to do is just tie the two lines together, but this I think also controls the temperature also of the system so if omitted you would have to find another way to regulate the coolant to the heat exchanger which would be no problem. There are lots of different ways to do this

Also thanks to David he found the wiring diagram for the unit. It has a very early form of CAN and at this point in time I see no problems with it. It looks to be nothing more than a fancy version of OBD and doesn't seem to control any of the functions of the unit. How ever if it did have to remove it I was planning to just replace the sensors with the Subaru sensors and the ecu wouldn't know the difference

I finally got my computer to read the electrical files but haven't located the wiring for the AC/Heater

 

[Brett Proctor]

This is the duovalve(fig 6)

Your going to need this (or make your own)for dual climate control. Doesn't matter if you have a 92-99 AC/heater unit or a 00-06, they both use this for dual climate control

If you pull the AC/Heater unit out of a car you might want to spend a little more time and pull this also.

Cost in the wrecking yard was only $11. Cost on the internet starts at around $200 and goes up from there.

 

[Brett Proctor]

Here is something that some may find interesting

If your going to use the controls from the donor car the fan switch doesn't have the conventional 3 or 4 speeds to it. It appears to be a potentiometer and you have variable speed settings from off to the "High" setting.

The controls are quit small also so finding a spot to mount them should be no problem

 

[Brett Proctor]

Found this

For those that have air cooled power plants this could be a solution to getting heat if your not using the VW's system.

96-144 volt 5,000 BTU 1500w Single Element Inline EV Coolant-Water Heater Kit


EV Source - 12V Electric Heaters

It looks like they require more than 12v to operate(could be wrong) but I think something could be made to get around that.
It says they will heat the water to 190*f and some come with a circulation pump.

Then you could use the heater part of this unit

To bad Yaughn doesn't post here any more, I'm sure he'd have some ideas

 

[Brett Proctor]

The "S" series Mercedes also Has these in them.

How do I know?? I found one the other day in a S 600 V12 Mercedes

Sorry its already taken but I hope this will help others locating one.

I will keep an eye open here and if I come across any more I'll pull them.

This is no easy task because the seats have to be removed to get to the mounting screws of the unit and the center console.
The problem is getting to the mounting bolts of the seats. With no power to the seat(all the seats are power) you can't get to all of the bolts.

Your going to waste about an hour just trying to get the seats out of the way enough to get to the mounting bolts of the unit and console, and if you do get to that point, the seats will be worthless because of the damage that will be done to them.
So if you do come across one of these units and the battery has been removed from the car(all batteries are removed from their cars at the yard here) it maybe best to find a battery to hook up to the seats so you can adjust them so you can get to the mounts. If you can do this then its only a couple of minutes it takes to get the seats out.

 

[Brett Proctor]

I know a few of you must be thinking that a dual climate control in this car is totally stupid but the option is there if you want it and it was something that nobody thought was possible. Plus there are a few that like the thought of having it.

First diagram is OEM setup of the system


After some editing here's how it looks the way I plan to install it in the car



if the duovale is not going to be used just omit it and replace it with a single shut off valve. I have a shut off valve that came out of a Honda Civic that could be used if you choose to not use the duovalve. I need to dig it out and I'll post a picture of it

 

[islandman]

Your car is getting to be so OEM finished in so many areas, Dash, HVAC with dual controls, fantastic custom rear end....... its giving us all something to aspire to *thumbs up**rock on*

 

[islandman]

which is the Duo Valve, item number 4 on the diagram?

edit : ignore me I reread the post properly

So the valve must be able to close the flow off in stages based on the controls setting rather than a straight on/off right?

 

[Brett Proctor]

which is the Duo Valve, item number 4 on the diagram?

edit : ignore me I reread the post properly

So the valve must be able to close the flow off in stages based on the controls setting rather than a straight on/off right?

Yes #4 is the duovalve

Yes the heat is controlled by how much coolant flows through the system and the valve is what regulates the flow of coolant through the system.

Here is a valve that regulates the coolant flow from a Honda Civic. Uses a cable to operate but other setups could be made.

This would get rid of the dual climate setup

 

[Brett Proctor]

The controls are quit small also so finding a spot to mount them should be no problem

I guess a few didn't realize what I meant by small.

 

[Brett Proctor]

Had a little time to do some test fitting of the unit.

Found a couple issues to be aware of.

First is, if your thinking of mounting the unit under the dash on top of the tunnel it will have to be mounted with an offset for it to clear the gas pedal



Second issue I haven't confirmed yet, but just from visual inspection it looks like the pocket for the wiper motor may interfere with the fit of the unit if it is mounted in that location under the dash.

So before running out and getting one of these do some measuring first(dimensions of the unit are posted) to make sure it will fit in the location your planning to mount it.
Don't forget that there are drain openings on the bottom of the unit to drain the condensation from the evaporator.