After spending an hour or so searching for a post similiar to mine, I've come up with nothing. My '79 is a factory AC truck and I have replaced the blower fan hooked up the wires and I have nothing. So I used some lamp chord from the blower connection to the battery directly and the blower fan operates just fine. Problem is that from that connection the wires go through the firewall and then across. 1 wire connects to the firewall on the engine side upper center for the ground and the other wire continues to the driver side and deadends with a female connection, but where it goes from there I don't know.
Before I swapped out the blower fan the heater was operating. So I'm trying to trace it back to blower motor resistor pack, but don't know where it is or what it looks like.
If anyone has any other ideas I'm all ears...

Edit: I'm working from my '79 Bronco EVTM pg.41

 

If you dont find anything let me know. I have an old Motors and Trucks manual that was the BIBLE in the old days. Ill look up and see what it says. I put a heater core in my 79 F-150, but that was like 25 years ago. My memory aint what it used to be. I just put heater core and new blower motor in my 78 Bronco about 2 months ago, but it doesnt have AC and its a whole other thing. Easiest heater core I have ever done. If I can help I will surely do so.

 

Thanks Gator, I rigged it up with 2 wires coming straight from the blower motor pigtail to a key on location on the fuse block and the other wire to a ground point. I have operating heat for now, but sure would like to figure out what part or parts need replacing to get this operating correctly.

 

Did you happen to check the heater resistor located next to the blower motor.the blower motor high speed operates direct to heat blower motor for high speed fan and the other for the resistor to lower fan speeds.it is common the the resistor over time will burn out from moisture in the heater box.Check to make sure the the blower motor and resister plugs are not melted.for your high speed,check your fuses.Forgot heater switch in dash plug also melts.

 

these components for the heater I can't seem to find. Problem is I don't know what they are suppose to look like...

 

The heater resistor is located next the blower motor in the heater box,so if you put a wire to the blower motor you should see the resistor next to it.It should have about 4to5wires on a little plug!try and unplug it,it may be melted so hard to remove.it is held in with two screws or mini bolts.

 

1997 f250 heavy duty heater problem. Blows cold air, seems like a damper or
cable problem. cable seems to move normal on top of heater box. the manual
description to adjust the cable is different from mine. Any thoughts?

 

You can pull out the heater controls and check if the heater cable is still retained.if the cable casing holder has come off the control lever will still feel easy to move and same at the heater box.I believe on your model,the heater control on the box is on the drivers side near to floor and can be seen if the flap is moving with the cable.

 

clarification: is the cable casing that may need adjustment on the end by the controls or on the end by the heater box.
Thanks for your input.

 

The end at the heater box!

 

Is it possibly this connection:




or this one:



onthe second photo, the 2 wires come out of the blower motor are connected to 2 wires that I have connected directly to the fuse block. So first I know the replacement blower works and second I have heat. Now to troubleshoot either of the above photos can I just bypass 1 connection at a time or is there something easier. No wires appear to melted, so could this possibly mean that the fan switch is the culprit?

 

Yes very likely

 

Yes looking at pic,yes most likely problem.looks like someone's been into said harness.

 

Yes check heater switch,possible melted plug at switch.make sure you check for fused power at the switch.very important.there must be power to the switch,then it goes to the blower motor for high speed and then for lower speeds it goes thought resistor.looking at the pic,the heater resistor wires look good but you can check after switch inspection.

 

Sorry I might have missed it, but what photo are you referring to being the resistor pack?