The heater motor just does not put out much pressure. On defrost you can barely feel it. You can feel it more on the floor but not much more. I do not have the money for the Old Air system or the other one right now. Anything can be done to update the stock one?

 

It's an old truck. I'd make sure there are no leaks in the duct work. Also be sure all flaps move freely and completely. Also, the foam seals where the flaps seat have probably turned to dust by now. As for the blower motor, check that it turns freely. A few drops of oil on the bronze bearings wouldn't hurt. Good luck

 

My heater core is shot and someday I'd like AC but I can't afford an after market unit so I'm working on finding a unit from the wrecking yard that will fit under the dash with a minimum amount of custom fabrication. I'm not hopeful this will work because I can't find any info from anyone that has done it. I think that if f it were easy there would be plenty of info on how to do it an what unit to use.

 

I took my old heater core to a radiator shop. They took the end off with the piping and attached it to a new heater core for around 75 dollars.

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My heater setup came out of a 55 and I replaced the motor (12v)crossing over to a VDO Pm350 motor which can be had at any parts store for 30 dollars. All the catalogs list the original motor for 75 dollars and up. Only modification needed was to drill the fan blade center shaft hole to 5/16"

 

Make certain the mouse family has not set up housekeeping in the heater or the defroster duct area. Ask why I suggest that you look there. If the hose going in and the hose coming out of the heater are both hot the problem is not the core.

 

It would help to know what kind of heater you have. Is it the small box heater, or the larger unit with the outside air intake?

 

If your not getting good air flow which is the way you laid it out, it can only be one of three things, 1. your heater core is plugged with debris (this happens a lot), 2. your selector valve (shuttle valve) is not working (maybe the cable has come off or the seals are totaly gone), or 3. there are so many air leaks between the air box (fan housing) and the outlets that all your air flow is bleeding off before it gets wher you want it.

When I pulled my heater the front (intake) side of my heater core had about 1 full inch of leaves, grass, etc packed into it, the blower motor could not suck air through it. I would start there and work back thu the system.

 

It is the larger unit with outside air intake. It has been changed over to a 12v motor. Not sure what kind of motor. The previous owner had changed it already and has it hooked to a toggle switch. Dont know for sure but believe it is only a single speed. I replaced the heater core a year ago. When I operate the cable I can hear the butterfly open and shut.

 

Is the fan spinning the correct direction? If wired wrong and spinng backwards could cause this.

 

Does the motor appear to spin fast enough? Did it ever work acceptably? I wonder if it just may be tired? I know that question may be a little tough to answer if you don't know the history of the motor. I am also running a "who knows what" 12V blower motor the previous owner installed long ago, but it puts out pretty good airflow.