Heater Blower Upgrade Question

Go back to AZ and ask for the one without AC and compare. I think you will find that's the ticket..

I'm thinking you have the "premium" motor upgrade and are now in the same predicament I was in. Your only option is to cut away part of the plastic housing that the motor goes into. If I remember correctly, where the motor goes in is kind of concave. Cut away ALL of the concave part so that it is now just a flat opening. The motor should now fit without the fan catching the sides of the housing. If it doesn't fit, add some foam padding (it's like a foam insulator type stuff that is sticking on one or both sides). I used this foam stuff as an insulator and it works nicely. You'll also have to widen the firewall hole a bit ...after that's done get some heat-proof silicone and silicone the motor on the engine side to seal it.

The biggest tip I can give you is to keep TESTING THE FAN out at each step of reinstallation. The tightening of the housing and all of the reinstallation procedures can flex the plastic housing and cause the fan to rub. I had almost completely reinstalled it and when I went to test the fan, it was stuck to the side of the housing again ...very annoying.

Good luck.

at Autozone I had to go through a few GM cars to find the right one. All of the Blazers had the same part number, I tried something like a 77 Camero and it was the right one.

AutoZone sandbagged me on that one too when I did the swap. They sold you the wrong motor or, rather, the right motor but not the one you wanted. Take it back, bring your old Jeep motor with you and compare it to a few other GM motors. Beware: The wrong motor will put the squirrel cage in the wrong place and it _will_ bind in the heater box. Go to the sales associate that is old enough to not have pimples, s/he'll know how to find parts that don't easily show up on the computer.

I didn't know that there were two motors for that GM application and ended up making mine fit by changing the spacers around and adding a shim between the motor flange and the heater box, but I'm told that the other motor is a drop-in replacement (except for the firewall hole.) Don't try to make it fit, your time is worth more than that.

Resist the temptation to use silicone around the heater motor at the firewall when you get it back together. Silicone, unless it is specially formulated for windshield installation, is reputed to eat paint and metal. I used some butyl rubber I scored from a glass shop. Butyl is like chewed bubble gum, stays tacky and never hardens.

Oh and, depending on how old your Jeep is, think about your heater core while you've got the box out. Do you want to replace it now, or wait until later?

Good luck.

It looks like we have a winner! The fan without the AC fits just fine. Some other notes for anyone planning on doing this:

2) With the PM102, I'd use a bit to make a 3 1/2" hole, not 3 1/4" hole listed on the web site. I think the dimensions have changed since the web site was last updated, as mine fits pretty darn good (better than the factory fan).

4) Replace the heater core. It's only $35, and not worth it to pull the whole thing apart again.

Congrats. And a hearty "neener, neener!!" to all those other suggestions. ;)

pm:

You probably have other problems somewhere ...the blower upgrade works on my defrost vent but barely on any of the other vents ;p

You have cable issues then. I am in Canada and drove one winter with just the bikini top and half doors on and that GM blower would still keep my feet and my bare hand on the shifter warm. (I used to smoke cigarettes so it was handy to be able to have one bare hand free)

Mike

griff>

HomeBrewer ( snipped-for-privacy@cox.net) wrote on Wednesday 08 December 2004 07:05 am:

It helped quite a bit - before it was barely a trickle, even on high. But I also replaced all of the weather stripping inside of the housing, better seated the defroster pipe that runs to the defroster vents, and cleaned up and re-sealed the rear cover of the housing.

When I left work this morning it was -24 degC my windows were clear all the way home on the 50 km highway drive, before doing the upgrade