I have a 2006, e 350, extended, 6.0 diesel and was wondering if anyone has installed a rear" bus type"heater and where you would tap it into foe coolant circulation. Thanks, Tom

 

I did this my own self----used Pro-Air brand auxiliary heater---works great!

 

Not sure of the later models but in my 1994 E-150 Ford effectively Tee'd off the input flow to the front heater and Tee'd the return in the same fashion.

 

For my installation there are several controls added along with vacuum-actuated valves that re-direct coolant flow in order to get maximum heat to the rear. When rear heat is commanded hot coolant flows first through the rear coil then to the front cabin heater, all through heavy duty automotive heater hose insulated with commercial A/C line materials.

To me running them through a Tee fitting doesn't allow any control, both coils essentially running all the time even when not needed. I do know if I'm trying to warm the van front and rear all at once it takes seemingly forever---my scheme allows for a quick warming of the front after which the rear unit is engaged.

Do keep in mind my truck is a cargo-only work van, a soft curtain dividing the front seating area from the rear which is in itself very helpful to creature comfort.

 

Granted the control is far less, but that's what Ford shows in the shop manual. Full flow/full time. The design heavily depends on the blend door for control in the front cabin. I suppose the fan speed is it for the rear. The rear fan does have an "off" position unlike the front. I just finished trouble shooting a fan speed/blend door problem. Now, with it working correctly the front heater is a "nuclear reactor"!

 

Been wanting to put one in the rear of my 73, my 89 G20 and Suburban had rear heat/ac, and as fun as things are, I can't remember how ether was hooked up to get an idea how to run this.

 

Maples, I like your avatar. Looks similar to a sign I made for the side door in my van.

 

A minor thing with the vacuum operated coolant valve versus the blend door is that you can control amount of heat and you have heat (or cool) available at all "level" settings with a blend door. Our vans with aftermarket rear heat have the rear coolant vacuum valve open when you are set to Defrost, Floor, or Mix. If you go over to Vent, or any AC settings it closes. For the most part this makes sense, but it can be confusing when you are on Vent getting heat out the front but no heat in the rear. Or on a mild day when you have the front blower set on mix and a cool setting, but the rear is getting full on heat even though you're set in the blue up front.

We've only got one van with factory rear blower and fortunately I haven't ever had to really investigate it other than to change a blower motor. If it does run coolant to the heater core back there full time, we haven't noticed it to be any slower to heat up than the other vans. My guess is the thermostat is the main factor with warm-up time. This is Minnesota so the heater tends to get a pretty good workout.

That said, I wouldn't hesitate to do the aftermarket coolant valve thing. I just view the blend door approach as a little more refined.

 

My design and use of vacuum-actuated valves is just on/off to direct coolant flow, not modulate that flow to affect cabin temperature. I fully agree the blend door approach is the better method, having dealt with more than a few cars & trucks with the cable or vacuum controlled modulating-type coolant valves.

The Pro-Air unit does have a 3 speed blower and because my van is cargo/work only its typically set to high. Since I have two zones mostly divided one from another comfort settings are important only in the front---all factory features still fully functional.

I do use the factory spec'd 195* t'stat but honestly never really timed how long it takes for both zones to heat----probably too impatient and accustomed to my self-designed system by now.