Okay, I've gone through both my Haynes manuals and a 70's Ford Pickup Repair book, but none of the A/C blower assembly pics look like the one in my 1978 F150 Ranger. I'm still searching this Forum for a picture of someones blower motor assembly. I took out the air ducts and vents and removed the heater core hoses. Now I'm trying to find out exactly what parts I need to remove to get to the blower motor for cleaning/replacement. Also, is the heater core seperate from the a/c evaporator core? I'm thinking that the blower motor might be in the big black metal and plastic box in the engine compartment on the passenger side firewall.

 

I have the same truck.

The heater core, Evaporator core and the blower motor are all insdie that black box on the passenger's side of the truck. The box comes apart in 2 pieces...one comes out form under your dash on the passenger side in the cab, and the other comes out from under the hood. I took this thing out of mine last year to replace the blower motor and the heater core. It isn't hard, just time consuming. And you have to either take the fender or the valve cover off the get the top piece of the box out from under the hood.

Let me know if that isn't clear and I'll take a photo of mine as it is assembled and post it here.

 

Thanks, kc5hwb. Some pics might help me. Do you have any pics of your removal and replacement? Do you still have the old blower motor to take a picture of? Did yours have two seperate coils; one for the heater and one for the evaporator? If I remove the inside plastic panel first will the box assembly in the engine compartment want to fall down? I wonder if I need someone to support it while I remove the inside pieces? Did you remove just the inside passenger side plastic that goes to the kickpanel air inlet rubber tube? I hope I don't have to remove the center plastic housing pieces.

Why did you replace yours? My blower motor was barely blowing at any speed setting and now it does not blow at all now. And the a/c temp wasn't very cold so I figure the evaporator coil might be blocked with years of dust and whatnot.

FYI, I just checked the jc whitney site and the blower motor pic they had listed for the 1978 F Series Pickup looked like the style that belongs in the early model F150 or Broncos.

 

Except for the link I'm sending you via e-mail

I have this


and this

 

Cigar...I don't have any pix of my replacement of this unit, sorry. I replaced the heater core because it was leaking and I did the blower motor because it was making a loud noise. If your A/C isn't blowing cold, I doubt that it us because the evaporator is blocked. Check the freon charge and that there are no leaks and check the condensor.

The heater and the evaporator are 2 different units.

Once you take the inside part of the box out, the front part should not fall...at least mine didn't. It was a pain getting the part out from under the hood.

I'll take some shots tonight of it and post them here.

 

Remove the big black box from under the dash, and just lay it on the floor board. The big box outside the cab has 3 or 4 studs that stick through the firewall, so it won't fall out by just removing the inside box. Once you get the inside box out, wiggle the box out side around until you get it out. You will see the evaporator in the big box from the inside of the truck once you remove the inside box. I pulled the boxes out of 2 trucks so far, and didn't have to remove the fenderwell or valve cover. It just takes a lot of patience. I added factory A/C to my truck 2 weeks ago and had no problem getting my box in, and I have a 460.
Any way, once you get the box out from under the hood, you'll be looking at the evaperator. The evaperator has a few screws that hold it in the box. Remove them to access the blower motor and the heater core.
Doc

 

Mine is a 400 with bigger heads and valve covers. It won't come out without taking the valve covers off, believe me, I tried...

So it depends on what size engine he has. Also, mine is factory air, and the box is bigger then tha stocks heater-only trucks.

 

Thanks all!!! The pics help. My setup is very similar to the pics Dennis posted. I've got the factory a/c and a stock 351m motor. Will the blower motor be bolted to the firewall after I remove the black box under the hood? Or is the motor buried inside that black box? Should I also disconnect the evaporator lines before moving the box under the hood? I'm not worried about loosing freon. I think it might already be gone. It blew cold for a month last summer then just barely blew cool. I plan to use a R-134 conversion kit while I'm tearing all this stuff apart anyway.

 

The blower motor is inside the box, not mounted to the firewall. And the 351m and 400 engines are the same on the outside, so likely, you will have to remove your valve cover. Mine would not come out without doing so.

You will have to disconnect the lines going to the evaporator and lose the freon, unless you have some way to capture it.

 

I put the factory A/C set up in my 73 that has a 460. I wasn't aware that the 351M/400 was bigger than a 460. I also pulled a box out of a truck at the U pull it yard last week for my uncle that had a 351M. I did not take anything loose except for pulling the dip stick out of the transmision, and what ever had the box actualy connected to the fire wall.
Doc

 

If you just really want to pull the box from under the dash you can. But it's not necessary.

Try this:

https://www.ford-trucks.com/article/...es_Trucks.html

You can remove the heater core, ac evaporator, and the blower motor. Should you wish, it's not even necessary to vent the ac system and loose what freon you may have.

 

Thanks fellas. I read through that article yesterday. I wish it came with detailed pics. As I piece together the info on these replies and the pics I think I will be able to do this with relative ease. I think this is starting to sound like more than a 2 hour job. I don't think I'll have 2 hours of daylight to work with tonight, so I might start tearing into it on Saturday morning. I'm tempted to take pics as I go along to make sure I get everything put back properly, and who knows, maybe pics would help those whom try this in the future??......

 

Hey Cigar, This isn't a real complicated project, but if you've never done it before....I would not try to attempt it in less than a half a day. This will insure that you don't have to rush, and can make sure you get everything back together properly.
I didn't know you could access the heater core and blower motor like 76 supercab said, I thought you had to pull the box out. If it will work like the link that he shows, it should be a lot easier. I can get the boxes out with out pulling anything off of the engine, but it's a huge pain. If you have to pull the box out there is one thing you can do that is quick and easy to gain a little clearance. There are 3 bolts that go through the fenderwell and the little bracket that bolt to the cab. That box will sometimes hang up on one of those 3 bolts. The bolt goes all the way through and there is a nut on the other side. Take the bolt out and it will give you a little more room to work with. Do not take out more than one unless you mark where everything was for reassembly. Otherwise your going to have a problem getting your fenderwell lined back up properly.
Doc.

 

The heads are bigger on the 400...not the engine, obviously.

If you can do it without pulling the valve covers, great. That will save an extra step. And yes, you can do it without pulling the inside box out....I pulled mine out so that I could place some extra weather-stripping on the seam to prevent cabs leaks and noises. But that isn't a necessity.

Take doc's advice and plan for plenty of time. This isn't hard, but it isn't something you want to rush either.

 

I've done the job 2 times using that procedure. Once for the blower motor and once for the heater core. The procedure is word-for-word straight from the Ford factory manual. Just take your time and read the procedure thoroughly. I would allow 4 hours for the first time but you will probably get it done quicker.