Like the title says, is there a foolproof way to tell if I need a heater treaters? I looked at the blend door motor yesterday, it does move when the temp knob is turned but I can't really tell if the door is moving at the same rate. Am I going to have to take the motor off and remove the little piece just to see if it's cracked?

 I'm asking because I like some others on here have heat, it's just not as hot as it should be at the vent. 

 A year or so ago I replaced the heater core and a/c coil and inspected the door seals. That should all be good. Seals were in good shape and everything seemed fine. Since then (and before) I just don't get piping hot air coming out of the vents even with the engine twmp gauge reading 190°. So I figure it's time to check the little plastic thingy in the blend door.

 Any thoughts?

 Wish I had a laser thermometer to check heater hose Temps. I know one gets pretty darn hot, can't hold onto it. The other is slightly cooler. You can hold onto that one.

 Like a little while ago on the way home from the inlaws this was my engine temp while going down the road 

 Sorry, image is a touch blurry, a 3500 don't ride like a caddy on country roads 

 

 

 I think it's time for a new thermostat. I though I bought this last one at napa but not sure. 

 I'll drop the blower motor tomorrow to check for air flow blockage. If none is found then maybe pull the heater hoses off the block and flush the core into a bucket and look for debris. 

 I have a new radiator that I still have not installed. I should probably just swap them, flush the entire system, replace the T-stat refill with new coolant and be done with it.

All of the air that leaves the blower chamber immediately flows through the evaporator core.  If the evaporator core is partially blocked, then you will have reduced air flow from the vents - not reduced air temperature.  In fact, the air temperature from the vents would probably slightly higher because of the longer saturation time while flowing through the heater core.    You have not mentioned anything about low air flow - you have only mentioned low air temperature. 

 

It is possible the thermostat could be a problem, but I don't think so.  I run a 180° thermostat in my truck and my heater works fine.

 

I think that you are down to a partially plugged heater core, or the blend door actuator is not indexed correctly, or the blend door itself is damaged / not sealing.  I think it would be worth a try to remove the blend door actuator again and rig something to prop the blend door in the correct position to ensure that all air is flowing through the heater core.  If nothing changes, then you can rule out a blend door actuator problem. 

 

I know you will get it figured out.

 

- John

 

 

 

 

 I did not index the blend door motor when I installed the heater treater. I may do that today as well. According to heater treater the motor will relearn over a period if time. Not sure how long that will take though.

 Judging from my temp gauge on the dash I think my T-stat is not functioning properly. It may not be the root of the issue but a contributing factor at the least.

 Without an infrared thermometer I can't give accurate hose Temps but by feel the hoses seem to be somewhat close in temperature. I will remove the blower motor and check for debris today as well and maybe just pop the hoses off and back flush the core out quick just to see if it makes a difference.

 The Temps at the vent now are less than what I had right after I changed the heater core a year or two ago so something is up.

 I would like to do this systematically so I can find the true cause or causes. 

 Also, air flow was mentioned, I seem to have adequate air flow. I don't believe that to be an issue.

 Ok, got out there today after a trip to my local Napa store for a new thermostat, radiator cap and 6 gallons of coolant of the green variety. 1 gallon full strength and 5 of the 50/50 mix.

 I finally changed the radiator today, flushed out the block until I had good clean water flowing out. Also flushed the heater core both forward and backeards.

 After refilling the cooling system, checking for leaks I went for a 4 mile drive around the block to warm her up. The  parked in the driveway to measure Temps. With my scanner plugged into the obd port and a thermometer in the center vent above the radio I had 181° engine temp and 118.9° at the vent.

 I then removed the blend door motor again and indexed that accord to instructions from heater treater. After this part I went for another ride around the block, 4 miles and checked Temps again, this time I check vent temp at the floor vent. I had 186° engine temp and 138.9° at the floor vent. Much better.

 I believe that it needed the flush out, I know it needed the radiator (I've had it for a year) the driver's side tank had a Crack in it.

 My next concern I guess is the engine fan. How free should it spin by hand with the engine off? I have much better heat now but it still cools off fast once the truck is stopped and at idle.

 I'll attach a video of me trying to spin the fan by hand.

 

Ok, couldn't figure out how to attach the short video but if I spin it by hand, as soon as I let go it stops. No free wheeling at all.

What the heck is a “ heater treater”?

For the second generation Dodge Ram ('95-'02), this is about the blend door actuator.  It is the only electronically operated ventilation door on our trucks.  The rest of the doors are vacuum operated.  The blend door's OEM "interposer" is plastic and prone to cracking or just wearing out.  The replacement interposer is steel.

 

- John

 

Thank you Sir