I just purchased a pretty nice, older ford E-350 superduty van. It has rear AC/Heater. The front heater works great, but the rear heater does not blow hot air, just cold. There's no place to adjust the temperature on the rear heater (it runs off the front controls).

The Haynes manual doesn't go into the rear heater too much, so I was looking for some direction. Does anyone have any suggestions on where to start my diagnosis?

Thanks for your help, Ian

 

Update:

I did some snooping around in the rear heater... The condenser in the back is getting hot, but there's no air going through the intake to pass through the condenser. I'm not sure how to get in the compartment to check things out though.

 

Turn on the rear fan for a start.

Make sure that the Front control is on "Heater".

NOT AC.

 

Well... I guess I asked for a place to start didn't I? Thanks gearloose1. At least you didn't tell me to open the door, insert key into the ignition and start the engine.

I've gotten to the blower motor in the back. It seems that when I turn it from cold to hot on the thermostat, the door inside the blower assembly doesn't switch from A/C to Heater. The vacuum line looks like its in good shape, but makes no sound when turned from cold to hot. Has anyone run into a problem like this?

 

More troubleshooting resulted in getting the heater to work by disconnecting the vacuum line that goes to the blend door actuator. When I disconnected it, the door opened right up and switched from AC to Heat. So no matter where I the thermostat is on the panel, the vacuum line is keeping the heater door closed. Sounds like an instrument panel issue. Any help from here?

 

Vacuum control switch on the front panel is the next place to check.

Find out why it is not delivering or shutting off vacuum.

Is the line normally on (vacumme) or off (no vacuum)?

If you can find the routing... sometimes, the line is kinked... or alternatively, plugged.

Compressed air carefully used can help --- be careful not to damage anything using too high a pressure...etc...


Do you have a kinked line?

Check that first.

Then check the dash switch and see if the line is pulling vacuum...

 

Did you end up figuring out what was wrong? I've got the same problem in a van I just bought. Haven't gotten into it yet but now that I've got a place to start I might get it pulled apart over the weekend.

Thanks!

 

I have the same prob with my e150.....any solutions?>???

 

Do you have a Club Wagon or other high trim level van---or is your rear heater assembly uncovered?

 

hi guys,
i have the same Problem. I have a '92 E350 7,3l Diesel
I found an open connection of the vaccuum at the right side of the heaterbox in the front but i cant find the hose which seems to fit in there.
It seems, that the hoses which go into the rear heaterbox are not getting warm.
any suggestions?

 

Can you disconnect the vacuum hose at both ends and blow low pressure through, to clear any obstructions?

 

I disconnected the blue vacuum hose in the back today and then there was air blowing only on the floor and still cold. I connected it back and in ac and venting mode it was blowing on top again.
Then i checked the vaccumhoses in the front. looks like this. four connections are open, but there are no more hoses to connect.





is there somewhere a valve i can check? i could not find the heaterhoses for the rear in the motor compartment. i only found the a/c hoses.
ACin the back is working also when there is warm air in the front

 

Would it help, if you plugged the open ports?

 

Hi guys sorry for coming back to this this late.
I found out why its not working. Somebody disconnected the hoses of the rear heater right at the motorblock. Seems like there has been a former problem with a leaking heater or something.