blazer heater motor upgrade

jeepofino

New member
If you go with the standard duty 73 blazer heater blower motor do you have to do any mod's on the fire wall for it to fit? Are the mounting holes and all that stuff pretty much the same as on a 82 cj7? Is there a big difference in the air flow?
 
I'll let you know how it come's out. I plan to do it tonight of tomorrow(thanksgiving) so maybe I'll have some strong heat by the weekend
 
If you know a comercial electrian call em up and ask if they have a knok out set if they do ask if they will do a hole for you 3.25" to 3.5" and it will only take a second or two. Nice clean job too. PASmokeater did mine. tug
 

I successfully got the motor and hole cut but in taking the heater hoses loose the fitting on the core broke. Yesterday being Thanksgiving everything was closed so today I'll get what I need to hopefully finish. I can tell from the bench test it will be a lot more air flow. Doesn't Jeep stand for just empty entire pocket? You just gotta love em tho.......It was a good time also to clean up a lot of loose junk behind the dash.
 
I did the mod today as well. Other than chasing parts it was pretty easy. Autozone gave me a heavy duty motor instead so I had to go back and get it switched for the standard duty. The low speed on the new motor is like high on the old. I will see how it heats in the morning. The motor is 16.99 at autozone.
 

Hey forget the SOA for now it can wait till spring, this is my next project. It's supposed to be -17 by Tuesday. I need heat. While i'm at it i'll put in the block heater.
 

I used a sawzall to cut the firewall. It is not the best looking but it only took about 5 minutes to cut a bigger hole. I did cut it too big because the heavy duty one was a little bigger. Yes the light duty one for the 73 blazer was 16.99. It is very funny because the heavy duty one that did not fit was 13.99 go figure. The part you need from autozone is b102 I think, I am not sure about the letter. It works great.

If you go to the link above it explans very well. I do have a few suggestions. Do not unhook the cables. You can unscrew the covor over the motor which takes care of that cable then I just pulled the right side wout and did the swap on the floor of the jeep so I did not have to remove the whole assembly. I also took the battery tray out and cut from the engine bay to make the hole larger. I also did not remover the dash. I only had one problem. The area around my antana was dented in so I had to remove the antana. I hammered it out and when installing the assy I had no problem. Good luck.

Is the old Jeep moter a 3 speed? I thought mine was only 2 but when I hooked up the blazer motor I had 3. I thought this was odd since the switch is not differant.
 
My switch is a 3 speed. Will the fan blade part of the jeep work? I tried to pull off the cover under the dash and one of the bolts is really hard to get to next to the side of the jeep (by antenna). I don't want to start this until I know it all.
 
The bolts are all in the engine side. I took the cover off of the fan so I did not have to undo the linkage. It took me 1 1/2 - 2 hours for the work and my 3 trips to autozone to figure out what was wrong with the motor was another hour. The fan blade will work if you get the right motor.
 

I am looking at the write up and it says that you need to fool with the heater hoses, do you really have to. The cover I tried to remove is the one all the way on the right and it has that vent that you open for fresh air. Is that what need to be removed so the whole dash doesnt have to be removed?
 
Yes. You have to remove the whole assembly that goes halfway across the Jeep. Everything mounts from the back side of the assy. I figured the 6 screws for that was easyer than taking the linkage off so I took that part off but you can remove the linkage instead. There are 4 studds that go through the firewall, you have to remove the nuts. 1 is dead senter right behind the valve cover on a 258 so shold be close to that on the 4 cyl. There is 1 by the heater hoses, one on the bottom below the battery tray usually covered in mud, and one to the left of the battery tray I think. They are 7/16 nuts. I did not want to mess with the butterfly that was stuck on my radiater so I let the fluid drain out of the heater hoses into a bucked. The problem was that some got inside so I had to clean it up. If you have carpet I would drain at the radiator. It is a little tough getting the assy out because there are a few things going off of it. Above the motor cover there is one that is not attaches so you have to pull the assy down to miss it. The other thing to watch for is the Defroster tube going up around the center fo the jeep. I forgot to take it of and got a little tear in it. I am not sure how to remove it but I think I saw some clips.

Remove the 5/16 screws from the back of the motor and remove it (remove the wire from the firewall side before pulling the assy out.) Next cut your hole in the firewall bigger. You should have enough room on either side to get to it if you removed the battery tray. Switch the fan onto the new motor and reinstall it. Make sure you use the right set of holes so all 5 line up. They reinstall assy and fill radiator up.
 

Ok, thanks for the help, I am just not sure if I am going to want to get into that right now (time wise). I need a new motor as for mine is acting up, so I might as well upgrade to a blazer one. Thanks, hope I do it soon
 
It is a really learn as you go not to tough job that you can do. You will get a chance to clean out the air box and make for cleaner heat. The heating preformance is worth the task at hand. Go fer it dewd! tug
 
bryanjeep said:
I am looking at the write up and it says that you need to fool with the heater hoses, do you really have to.

Absolutely!

You will need to disconnect the heater hoses from the heater core in order to remove the heater box.
Be careful with the coolant that comes out!
I would recommend some hose clamps to minimize spillage, but its gonna get messy either way.
Just get some large CLEAN jugs before you start to collect all the coolant you are going to have to drain.
DO NOT just let it spill everywhere, it is extremely harmful to animals like cats and dogs. They WILL drink it if they smell it because glycol smells and tastes sweet. Glycol will cause kidney failure if injested!

Removing the WHOLE dash isnt really necesary, but you will have to at least fold down the window, un-bolt everything and prop it open with a 2x4 or something. Just make sure you disconect the battery so that you dont short out your dash while you are doing it.

Anyways, its totally worth it, so do it mang!
You wont be cold this winter.
 

If you drain the radiator down about half way there will be no spillage at all. then remove the hoses at the fire wall. If you need to drive just double back one of the heater hoses to the goose neck at the engin and you can refill the radaitor and drive. I do not see the need to drop the windshield at all. just loosen the nuts holding the heater box in place remove the cables and pull it out where you can wiork on it. It is not hard to do. tug
 
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