Trying to get the heater working

[67Dart273]

Thanks for your photos, Tyler. Even though I don't have such a car, they are worth, as they say, a 1000 words!!!

 

[sargentrs]

Blower motor pics as promised. That crack at the top on the firewall is the only gap around it. Looking in you can see which direction the blades point, for reference. To get this in the same post, the blower/wheel assembly is a Denso AY166100-0402 and a Google Search says it fits an 03-04 Grand Cherokee. A quick RockAuto search does not show it in their catalog but they do list the Four Season's version. Advance Auto search has more pics and verifies it's the same motor. According to RockAuto it fits these models. Buyer's Guide: FOUR SEASONS 75743 Blower Motor DODGERAM 1500 PICKUP(2002 - 2009 )DODGERAM 2500 PICKUP(2002 - 2009 )DODGERAM 3500 PICKUP(2002 - 2009 )DODGERAM 4000(2002 - 2009 )DODGERAM 4500(2009 - 2010)DODGERAM 5500(2009 - 2010)JEEPGRAND CHEROKEE(2002 - 2004)

 

[sargentrs]

Back to the subject. After spending a quality 3 hours in the hot sun, I think I've got it functional. After scrounging around and digging up that old vacuum harness, I pulled the selector out and finally saw it had one intact. Couldn't see it from an installed position. So ran the missing line out to intake manifold and found the correct line for the water control valve so threaded it out the firewall too. Then set about verifying vacuum flow according to the diagram in my '73 manual. Got some really weird readings that made me think my selector was bad. So I set about, line by line, checking every in and out. That's when I realized that the PO had reversed the lines going to the heat-ac actuator. He had the red on the white connection and vice versa. Once I swapped those around everything fell into place. A final function test verified that I had vacuum to the correct heat and defrost routes which was my main concern. Also have vent function so that's a bonus. I'll make a metal bracket, I work for a fabrication company, to repair that busted case where the defrost actuator attaches. I've got a vacuum reservoir on it's way (thanks, Tony!) and going to order a water control valve tonight. Reinstalled the removed defroster duct and buttoned the dash back up. By next weekend I expect to have a fully functional heater and defrost.

Thanks to everyone for helping me with this. Not only did I get my car working but I have learned so much in the process. This forum and it's members are fantastic! Thank you all!

 

[sargentrs]

I feel a little silly asking these questions but this is my first encounter with the heater set up in a Dodge Dart and the manual doesn't really give these details. Also the scanned pics in the manual are a bit dark and lack detail that I might be to figure out if I could see it. So I've verified that I have vacuum in all the appropriate places as selected by the mode lever. However, I only have good air flow to the defrost vents. I'm still a little vague on exactly where the heat air flow comes out of the case. I expect to be able to feel a stream of air blowing out from the lower section of the case somewhere but don't. Does the heat come out of the large square door directly in the front, the one that the AC flow comes out of? Also, just to double verify, can someone please verify that this diaphragm is connected properly? This is the one on the top left of the case, under the dashboard. The photo shows how the PO had it connected. In this manner, the vacuum routing was not correct. After reviewing the diagram and tracing the hoses, I decided that the red line should be going to the LH port and the white line with the T should be going to the RH port. The white line with T being the line that splits between port #4 and vacuum transfer switch.

 

[sargentrs]

The next issue is with the heat-defroster actuator diaphragm. You may recall that the section of the case that it was screwed into was busted. I made a bracket at work and sprayed it with textured bed liner to mimic the finish on the case. Then screwed it into place on the box, put the selector in defrost mode to remove the vacuum source, marked and drilled the bracket and attached the diaphragm in the same position as original. When I applied vacuum to the diaphragm, I could see it was wanting to move but wasn't accomplishing it's task. I believe that the curved rod on the top corner, that I assume actuates a door, is actually in the raised position and applying vacuum should pull it down? It won't move. Is it already all the way down? Is my diaphragm mislocated? What am I missing? Thanks for your all your help with this!

 

[keith sims]

Ok... are you sure the fan is running the right direction? The original had one terminal so it was impossible to wire it backwards but since that one has two, then it's possible. Even if the HVAC has no vacuum, it will default to the defroster and heater normally.

Next, in the photo of the tan part of the selector:

There are only two hoses. You are missing one, the rear one. On my car, the front port(toward the trunk) has a green hose. When I say green I mean black with green stripe and that will apply from here on.

The rear port has a white vacuum hose. The green one leads out to the water valve, the white leads around to connect to the other vacuum lines.

Speaking of which-

There is supposed to be way more than just two vacuum lines connected to the selector. There is also a vacuum "harness" that has a molded end that fits onto another part of the selector. Take a look at the selector in this link and you will see what I mean in the 4th picture.

[ame="[URL]http://www.ebay.com/itm/1973-1974-1975-1976-DART-DUSTER-A-AC-HEATER-CONTROL-ASSEMBLY-PLYMOUTH-DODGE-/271463542929?pt=Vintage_Car_Truck_Parts_Accessories&hash=item3f347cf091&vxp=mtr[/URL]"]1973 1974 1975 1976 Dart Duster A AC Heater Control Assembly Plymouth Dodge | eBay[/ame]

The vacuum dashpot that is broken off the side of the box is the defroster actuator.

My guess is the PO did all that damage when removing the heater box to replace the core. You should go back and ask him to refund some money for the aggravation. The Factory Service manual shows exactly how to remove the heater core without pulling the entire box.

I have the vacuum diagram for the heat/air if you need me to scan it.

I need the Vacuum lines diagram to the switch head unit