Accessing heater blower motor on A/C equipped truck
 

Hello fellow cold folk. It's done got cold but i don't think my truck notices. When I crank up my truck in the morning, the door to my ducts thats above the passengers side floorboards opens. When I go to turn the heat on the blower motor squeaks loudly sometimes. Other times it doesn't but either way, when i have it on high , the air just isn't moving like it should. Could I be looking at replacing the blower motor and if so, when I go to get it out, how should I determine the life still left in my heater core. I would figure replace both while it's handy to access.

A heater core is not that expensive so replace it. You may have debris in your heater also blocking airflow. It is a PITA to take that heater apart...

OK. I'll bite. What's a PITA?

Pain In The...

Just one of many abbreviations used on the internet.

I don't know what a PITA is, but I have mine apart right now. I have a 1974 F100 4X4 with factory AC and like you, I did'nt think I was getting the airflow I should get. It's a real chore to get at that blower motor you have to take the whole airbox out, inside the cab and also in the engine compartment.

I found a 1 1/2" X 2" piece of foam weatherstripping inside the squirlcage, along with a few other pieces of un-recognisable garbage inside the airbox. I also found that the foam seals on all the air doors were rotted and what was left of them is satuarted with dirt.

I also found a broken piece of the airbox, which either I broke getting it out, or it just cracked sometime since 74. In any case, I've got a lot of fabricating to do, to get it all back together, sealed and working as it should.

While I'm at it, I'm thinking about changing the refrigerant from R12 to something easier to get. I'm putting in a new compressor, dryer and purge valve, so now is the time to change. Anyone have experience with the R12 subsitutes? Do they work as good as R12? Or would I be better off switching to R134?

Oh, Pain in the.... I agree, only I would add Gaint.

As long as you are changing out AC equipment, -get the right parts and convert to 134a. You can find more info in the HVAC forum.

how does the first box right above the passengers floor come out. i removed 3 nuts ans one screw. what else is there. Im also trying to get the duct that runs into the side kick panel out. i got 3 screws out. what else is there

There may be another way, but the only way I could see to get at it was to take the air box inside the engine compartment out too.

There are six bolts that secure the inside the cab half of the air box to the outisde half. Those bolts pass through a flange on each half of the airbox as well as holes in the firewall, which is what holds the airbox in place. All six have to be removed before you can split the airbox. After you get all six bolts out, it takes a putty knife or something to pry the two pieces apart because they are sealed together with a sort of duct seal, or putty. Be real careful when you pry them apart, or you will break a piece of the airbox flange off like I did.

After you get the airbox apart and out of the truck, you're a little over half way there. The fan motor is buried way deep in the outside half and I think you will have to remove the heater core as well as a couple of the dampners. I think you will also have to break the AC system open in the process.

Like I said, there may be another way to do this, but I am replacing all the AC hoses and equipment anyway, so I just took the @$%#$%@@^ thing all apart.

It is a GPITA!!

okay i got that part. I am seriously going to clean that nasty thing. The air im breathing in the cab moves though that. Ewww. Any way I guess the next step is to go under the hood. The ac system is already opened. How many bolts and unforseen connections hold the outside part into the truck. I may stop where I am and continue this next weekend. I only have 1 more hour of day light and tomorrow I have to go to school and work.

You DO NOT have to take the Assembly out from under the hood and Its not that big a deal to change out a Blower motor.

Well if you have done so BigBully then how did you do it. I would like to avoid the process of taking stuff out from under the hood. But it you have a simpler method please share it. Im open to your advice.

what happened to bigbully? anybody else know how it can be done the way he says it can?
If somebody can come up with some pics that would be helpful. Non-ac systems are fairly straight forward. But AC equipped trucks need some walk through. Maybe this this thread can be made into the main source and referred source for those who are freezing their butts off.

(Dirty Harry voice) Ok Punk. Just look up in the upper right hand corner of THIS PAGE. Click on the button that says "Tech Articles". Follow that to an article posted in 1998 titled "Heater core removal". It's all there.

(Normal Voice) Seriously, it's all there. AND following those instructions you can R&R a heater core and blower motor in less than a couple of hours. AND YOU DON'T HAVE TO VENT THE AC!!!!!. Done it twice myself.

Listen here guys. My blower motor burnt up while I was blastin the AC last summer. Here's what I had to do to get it out.

1. I had to drill the rivits that hold the outer cover on the assemble under the hood.

2. Then I took apart something else I believe.

3. Then I took a freakin Dremil tool and cut the blower motor out leaving the ring INSIDE the assembly box.

4. Put my new motor in with the flange on the OUTSIDE and put the nuts on the inside using the old flange to help make it stronger.

5. Worked fine.



On another note...I now have a heater core leak. My heater has been a POS since I've bought the truck back in 2001. Does anybody think the old leaking core was plugged or something? The lines running in and out were always hot. When I noticed the heater core leaking, it started blowing significantly warmer air. I need some recommendations on how to do a heater core replacement on a factory ACed 77 F-150. Thanks.