Half-baked rear heater motor rebuild (it’s so crazy, it just might work) (1 Viewer)

[lelandEOD]

I’ve had zero luck either finding a replacement blower motor or a shop willing to rebuild the brushes and bushings in my rear heater blower motor.

At Pick-n-Pull, I eyeballed a rear blower motor out of a third GEN 4Runner that looked like the body and mounting flange were very similar to a -40 (although the mounting flange was on the wrong side of the motor). Since it was a ‘half off weekend’, I bought it and brought it home.
Today I got around to playing with the thing and think I’ve found a somewhat half baked solution.


Dead motor:

 

[lelandEOD]

I used a spot weld cutter with my cordless drill and cut the 4Runner mounting flange off then turned it around and put it on the bottom to check for fit.

It’s so crazy, it just might work!

 

[lelandEOD]

I played with the flange height until I found the proper height for the fan blade to clear the housing, trimmed the excess shaft length, and bored out the fan blade hole diameter to .265”.

 

[lelandEOD]

I haven’t tack-welded the flange to the body yet but when I do, I’ll be sure to avoid welding near the magnets to not melt the glue.

Dang if I don’t think this’ll work!

 

[emac]

looking good! Have you tested the new motor? The old motor grounds through the mount, so both wires are hot going to the motor for speed control. Make sure you know how the new one is wired.

 

[lelandEOD]

Thanks!

I haven’t wired yet but it should not be a problem. I just wanted to test for fit first.

 

[1969FJ]

Very good.

 

[thebigredrocker]

Genious idea!

If a guy were to scuff the paint, do you think JB weld would have strength enough to hold it?

 

[emac]

Could you rivet it?

 

[Nader]

That's clever, but I think you're going about it the hard way. I'm also re-purposing a later fan motor to my rear heater, and had the same issue of wrong flange height. I simply made some aluminum spacers to make up the difference. Motor shaft on mine also needs to be trimmed.

 

[thebigredrocker]

That's clever, but I think you're going about it the hard way. I'm also re-purposing a later fan motor to my rear heater, and had the same issue of wrong flange height. I simply made some aluminum spacers to make up the difference. Motor shaft on mine also needs to be trimmed.

View attachment 1616826

Was your fan 1/2 price though

Nader, how long are those screws? Do they hit the factory holes?

My 71 fan motor rebuild turned out to be a D+. Only runs on high and quite noisey. Might have to get me a 4runner motor

 

[Nader]

Flange hole spacing is identical. The spacers are solid, I threaded them on both ends so it's screwed from both sides. Even easier solution would be to get long screws and double nut them around the flange and base.

 

[lelandEOD]

That's clever, but I think you're going about it the hard way. I'm also re-purposing a later fan motor to my rear heater, and had the same issue of wrong flange height. I simply made some aluminum spacers to make up the difference. Motor shaft on mine also needs to be trimmed.

View attachment 1616826

Great minds think alike!
I also thought about spacers but after hunting around in my parts bins for a while I didn’t find anything I liked. Cutting the spot welds and moving the flange was pretty easy (if you have a rivet cutter).

 

[lelandEOD]

Genious idea!

If a guy were to scuff the paint, do you think JB weld would have strength enough to hold it?

If you can’t tack weld it, I’d try rivets before epoxy.

 

[MoCoNative]

After having my rear core repaired twice I decided to take it out. That and I put in a bench seat for the kids. Although my fan always worked. I put new brushes in the front motor once many years ago. What I did for a rear heater is squeeze an FJ80 rear heater under the drivers seat. It occupies the space under the right side of the seat and somewhat under the console. It's a little tight, but the factory tools and jack still fit fine. Hardest part was building a new vent cover arrangement to direct the air out of the cuttout where the rear heater lines used to pass under the console. Wires in the same as the original however and works quite well. Seems to put out good heat and is much quieter. FJ60 heater would maybe work too. Difference is the lines of the core go straight and down through the floor in an FJ60. The lines of an FJ80 heater have 90 degree turns and just fit against the floor of a 40. Would probably have to bend the lines at the core on a 60, could be difficult without kinking them.

I bet the motors would be similar to the ones used above if that was of interest too.

As for putting the bracket back on, I bet a quick tack weld would not hurt the epoxy of the magnets. Shouldn't take much to hold it really.