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Very little heat

niceolddart

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2001 Dodge 2wd 2500, V10 automatic. I have very little heat from the heater on this thing. Checked for hot coolant getting to & from heater hoses. All seems good. Is there any heating problems common with these trucks? Blend door not closing? Temp switch bad? The thermostat seems to be working OK. My last truck, an 87 D250 had great heat. I like old fashioned cable operated heater controls, you could "feel" if there was a problem, this electronic stuff, you can have it!
 
Both heater hoses are hot, one is not cold? The blend door motor is on the bottom of the heater case on the passenger side. Take a light and watch the motor while turning the knob, you should be able to see the shaft turning. If it is, remove the motor to see if the bottom of the door isn't broke.
 
Both heater hoses are hot, one is not cold? The blend door motor is on the bottom of the heater case on the passenger side. Take a light and watch the motor while turning the knob, you should be able to see the shaft turning. If it is, remove the motor to see if the bottom of the door isn't broke.
Both heater hoses are hot. I will check blend door operation as you suggest & go from there. Hopefully it dosen't turn into major project. Thanks for the help 65 sporty.
 
The blend door is working fine, both heater core tubes are getting hot, (I removed the glove box door & had access to most of the heater system) still only slightly warm air. A/C works well but I don't need it in January. Do the temp control switches have problems on these? All the other functions, Defrost, Floor heat etc. work as they should & no vacuum lines seem to be disconnected or pinched. I can live with the low heat but would like to find out why it's lousy. P.S. the bottom hose to the radiator is cool & top hose is hot & temp gauge only goes to about 150deg. I am replacing the coolant sensor, it's cracked & loose. I may replace the thermostat & upper hose anyway just because it doesn't look like they've ever been touched & may be stuck open a bit.
 
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Did you remove the blend door motor and check the end of the door to see if it's broken?
 
Did you remove the blend door motor and check the end of the door to see if it's broken?
I did not remove anything but the blower motor. I only saw the one door when I removed it & the glove box. It is vacuum operated & working fine. I did not see any broken spots on it (I have a very good view & access with the glove box removed) but I'm not sure now if I was looking at the right door. Where would the blend door be located if I was looking at the wrong door? It's not hard to pull apart again.
 
Take a look at this video, it shows the location of the blend door motor. With the motor removed you can see the bottom of the door shaft. The door you see that is vacuum operated is probably the recirculation door. I don't believe you will be able to see the blend door with the blower removed. I think the evaporator is in the way and the blend door is between the heater core and the evaporator. The blend door controls the air flow through the heater core.

 
You must have ESP! I was just NOW going to see where the blend door was on this thing on YouTube. Looks like a P.I.T.A. but now that I know where it is, I'll pull it apart & see if that's my problem. (I wouldn't be surprised, seeing that most of the other plastic items on this truck are cracked or broken) Thanks a lot 65 sporty for all the help, I really appreciate it. PS. I watched parts 1&2 also, just to see all of it, & as an old mechanic, I can say the guy doing the video kind of seems to know what he's doing & that's good. I've seen, & I'm sure you have too, that some YouTube videos are done by hack job artists & those are the ones I click off right away.
 
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Take a look at this video, it shows the location of the blend door motor. With the motor removed you can see the bottom of the door shaft. The door you see that is vacuum operated is probably the recirculation door. I don't believe you will be able to see the blend door with the blower removed. I think the evaporator is in the way and the blend door is between the heater core and the evaporator. The blend door controls the air flow through the heater core.


Well, I disassembled everything & the blend door & controller are working as they should. The plastic piece that connects the blend door actuator to the blend door itself was starting to crack, so I epoxied the outside of it just to be on safe side & will put I all back together later today. I will be replacing the valve cover gaskets so I might as well install a new thermostat, upper hose & related stuff since I have to pull the upper intake manifold off to do the valve cover gasket on the right side anyway. I'll see if the new thermostat helps. I don't think it's ever been replaced either.
 
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