Okay, took the 2003 e350 in for warranty problem, or what I thought was a warranty problem. Had to do with Cold air coming from ducts in front and Hot air from ducts in back while the heater temp guage was full cold. Did not seem right to me. Had a LONG conversation with the FORD shop Foreman and he was beyond words at how stupid a design this turns out to be. He went back over the last five years shop manuals and said they all function the following way -

Here is what we get with the FORD rear htr/A/C set up:

The rear ducts in the ceiling will ONLY blow interior air temperature or FULL Cold A/C, no heat. The Floor ducts for the rear air will ONLY blow FULL Hot air, never cold or warm. Sorry NO temperature control at all even though the 2003 Owners manual clearly states, to me anyway, that the front controls still control the temperature setting. See Page 53 of manual at the link:

https://web.msslib.dealerconnection....000c5880349e0f

Want to check it out for yourself? Select MIX or FLOOR and set your temp guage to COLD. Turn on Both front and rear fans. Rear floor ducts blow hot regardless of temp setting, front ducts blow cool air. Sorry people in back, you get to fry.

Next, select A/C and move the temp selctor to Hot or near hot (occasionally the A/C is too cold, or on a cold wet night you want the A/C to dry out the air abit but not be cold) turn on both front and rear fans. Rear Ceiling ducts will blow freezing cold A/C, front dash vents will blow warm A/C. Sorry people in the back, you get to freeze.

Someone PLEASE tell me they have a fix for this before I re-design the FORD design flaw so I can at least have SOME control over the rear temperature.

Or am I missing something???? Love the van but this seems like a major oversight at the engineering level.

BTW I checked my buddies 2004 E350 and it is exactly the same. He said his kids were freezing in the back when he had warmed A/C air coming out of the front vents. He thought he had a problem too. He said his Dodge ext van had rear air with temp variably controlled by front temp control.

 

clearly states it to me too.

I'd kick it up a level and get more senior people involved

 

Dear Quad,

I have owned four Ford vans over the years, and this has always been a problem. Driving south into the sun in the summer with the A/C cooling the front and the poor kids in the back freezing - I would just have to totally turn off the rear A/C.

The problem is very simple. The rear heater (and A/C) unit only recirculates the interior air (no outside fresh air). So in winter it is warming already warmed air, instead of -20F air, so it is really HOT. To fix this I put a heater valve from a 68 Ford pickup in the water line to the rear heater core. Then used a choke cable to control it (definately not automatic!)

The rear A/C is the same situation, it cools already cooled interior air, so it is really COLD. There is a vacuum water valve that closes off the water in the A/C mode. Unhooking this vacuum line and using the manual water valve you can blend a little heat into the A/C.

At least this is true for the 91 down body style. You would have to check the plumbing on the 92 up.

Jim

 

Can I assume that the front and rear heater cores on my 92 Hi-Top are plumbed in series ? Thats the way it appears when I look at where the heater hoses hook up.
One seems to go right to the front core and the other runs off in another direction, assumably to the back core. I flushed the whole system foward and back while the radiator was out getting repaired this summer and ran the garden hose in each heater hose till it ran clean. We've had a few chilly days down here lately and the heat blows out the front vents just fine but just ambient out the back vents in the overhead box.

 

Hum? I have never seen them connected in series. I have seen it with a "T" or more closely, a "Y" fitting in the supply and return lines.

On the 91 and older, each supply line has a vacuum controlled water valve in it. The front heater core water is turned off (vacuum applied) when the front is in "max" a/c, otherwise water flows so the temp control works. The rear water is turned off (vacuum applied) when rear is set to "a/c", and water flows (no vacuum applied) when rear is set to "heat".

It is possible the valve rusted closed with just plain water in it - where as antifreeze is kind of a rust inhibitor.

Jim

 

This is what made me think this because I read what you said in your other post about the 91 and down and I know that the 92 to 95 is a whole other story. I have no controls for the rear A/C or heat other then a fan switch in the front overhead console. The heater and A/C controls in the dash are standard controls. Unfortunately the company,Tiara Motorcoach went under a few years back and I can't get any info on this van.

 

My van is a MarkIII conversion, and I recently found a problem with the front heater: it just did not get warm enough. the conversion heater is plumbed in parallel, and when the fan was turned on, it warmed the van up.

So the problem had to be in the front heater; the watertemp was checked and was 80 C ( 176 F I think) so that should be OK(?)
Then opened the front heater, thinking the problem might be in the blend door, but in hot it was nearly fully closing and also in the opposite direction; adjusted the cable to make it perfect.
So what is my problem, with insufficient heat from the front heater? Did not get it back together yet. BTW, I found the heater core of an odd design, with large oblong tubes, instead of the 'radiator' style, is that normal?

Cor

 

I have a Mark III conversion also. I noticed my lower radiator hose has a plastic piece in the middle. 2 heater hoses run out of the plastic spacer. I have never seen this before. I assume this has something to do with the rear heater. Anyone have this setup? I can't get a good look at where they go, without taking off half the stuff on the front of the engine compartment. I suppose I'll find my answers when I replace all the heater, and radiator hoses next spring.
Anyone know where I can get that hard plastic piece in the lower radiator hose? I'll bet it's a Mark III part, and they went out of business.

 

I read somewhere on the net that Mark III had taken over Tiara Motorcoach, my van, a while back and now you say they went out too. I guess we're both screwed now.
If worse comes to worse and you can't replace that part you can always get a couple of copper T fittings and tie those rear hoses into the heater hoses from the engine to the front core.

 

Nightowl, That's what they told me last time I talked with them. That was several years ago. Maybe they did buy out Tiara. I know you can still get most of their parts, from center caps to seats, windows, pleated shades etc. I forgot the website, but I've got it saved somewhere. If you want it, let me know. I'll post it, or E-mail it to you.

 

Leo: Yeah, if you get around to it sometime, a post will be fine. Thanks

 

This one? www.v-sales.com Cor

 

Hi Cor,
Beat me to the punch. A lot of great links at that site for us conversion van fans. They have pretty much everything there, including Mark III and Tiara CD's, and wiring diagrams.

I was going to trade in after about 10 years, but with the availability of the conversion stuff, I'm thinking maybe another 10 would be nice. I love my 351, although changing plugs, and wires is practically a major job.

 

Back to the original topic re. rear heat/cold controls, the real mystery is who got away with this design proposal at Ford? It must have been junior engineer day when this project got tackled. Temp aside, and as long as I'm griping, the other thing it lacks is a way to recirc. air when you want to, so you don't have to suck on the tailpipe emissions from the diesel in front of you (or turn off the climate controls every time you come to a red light). I mean, how hard is a recirc. lever or button?

As a 15-passenger vehicle, you'd think some thought would go into the temp. for 13 of the 15 folks on board, though. Really thoughtless or overly cheap design, one or the other. It's my only real complaint about my van.

I've had the left rear panel off so I can try to rig a way to get some air mixing, but haven't figured out a way that won't look like intestines spilling out...

 

I have many times thought about the lack of recirc in normal modes. My thought was to use an emissions solenoid valve to manually apply vacuum to the recirc door. Then a miny toggle switch on the dash could electrically control it.
Jim