Yeah I'm going to have to bypass it and see what happens.. would that heat leaking past make the evaporator get that warm? And any solution to finding a seal kit for the blend door? My recirc door broke off a long time ago and put cardboard over the fresh air inlet so it only recircs now..

 

Go to your local hardware store, and have a look around, they will have some stick-on foam that will replace the stock seals quite handily.

 

It doesn't really affect the evaporator, but the air coming off the evaporater is first in line, it blows past the heater core 2nd in line, which blends the air and yes it affects the air greatly. Let's say the air coming off evaperator is 45 degrees. We'll now put a heat gun beside it and the air coming out will be about 75-80 degrees. Yes it is that dramatic. Putting the bypass hose on eliminated any heat what so ever getting to the heater core in the first place. So now it's just got cold air blowing by, only downside is, you will have to reconnect those lines to the heater hoses to have heat during the colder months.

 

His temps from the rear match his front temps so the same thing would need to be going on in the rear as well. And then the part of making the engine run hot is puzzling as well.

 

While I'm not doubting your results, it doesn't make sense. When the temperature is turned all the way to the cold side, the heater valve close and coolant flow to the heater core stops. So, there is no way for it to produce heat...unless your heater valve was bad and not fully closing.

 

Rather than spend money to find out, just place a piece of wood on each side of a heater hose and clamp them together to stop flow to the heater core. At least this will confirm or deny if coolant is still flowing through the core.

 

I was chiming in to tell you what solved my problem. It may not be the solution to his, but overall should certainly help the front atleast. I also have a rear system. I haven't even opened the box to look inside. It also blows room temp air. Not chilling air like it should. Blower works great. Air just doesn't get cold from rear.

 

As far as overheating, I notice these vans take alot to run ac. It has always made my temp needle spike up when running ac. I've got a new radiator, rad cap, hoses thermostat and waterpump and still run hot on hot days with ac on. I really feel like they should design a dual pusher fan for the condenser up front to help cool things down. I've seen kits online for the wiring but it starts getting confusing with dual fans and making a shroud that will fit.