Heater Motor Upgrade

SaddleUp · Feb 13, 2005

kwspony said:
My heater core took a dump today so I am going to do this upgrade. One question, my bronco has a metal heater box. Did they change to fiberglass at some point?

My 69 is fiberglass. If you use the stock EB cage then you should be able to do it without cutting.

Mark · Feb 13, 2005

kwspony said:
My heater core took a dump today so I am going to do this upgrade. One question, my bronco has a metal heater box. Did they change to fiberglass at some point?

Part of it is metal - the back side that mounts to the firewall. The rest should be resin (fiberglass).
My '66, '74, & '77 heater boxes are built the same.

Brewbro21 · Feb 13, 2005

I haven't done this conversion yet, but I just installed my centech harness and noticed that the two wires from my heater motor go towards the firewall and seem to be attached. Now I don't believe that there is anything for them to be attached to, or is there? Is that how those two wires route?

The orange and red I believe are the two that go behind the heater box. I think there is another wire also again though this is from memory.

brixter · Feb 13, 2005

I did this mod this weekend using the stock cage and ran into a problem , it was to long and hit the back of the heater box . So I went back to the parts store and got the chevy cage , but after putting it all together it was the same length as it was with the stock cage ???

Anyway I ended up cutting the back or center of the box a little bit (1/4")to allow the stock cage to fit . It works now , i am not real sure its much better which is kinda wierd cause when I tried it out side the box it was pushing a lot of air ?

kwspony · Feb 14, 2005

Mark Troy said:
Part of it is metal - the back side that mounts to the firewall. The rest should be resin (fiberglass).
My '66, '74, & '77 heater boxes are built the same.

Strange, my box is all metal.

Past_Miner · Feb 14, 2005

brixter said:
I did this mod this weekend using the stock cage and ran into a problem , it was to long and hit the back of the heater box . So I went back to the parts store and got the chevy cage , but after putting it all together it was the same length as it was with the stock cage ???

Anyway I ended up cutting the back or center of the box a little bit (1/4")to allow the stock cage to fit . It works now , i am not real sure its much better which is kinda wierd cause when I tried it out side the box it was pushing a lot of air ?

I had the same problem with the stock cage. I just couldn't get it to seat over the inlet involute inside the box. I went down to our local Carquest and had them pull every chevy cage they had until I found one that would work. I ended up using the standard duty cage, the AC/heavy duty cage also looked way too long, but bigger around. It may have worked if I had actually tried it. Either way I had to trim the box to get the cage in so I just used the shorter cage so I wouldn't have to go back to the store again.

It wasn't quite as cheap as I was expecting, but it was well worth it. Great upgrade.

cracker · Feb 14, 2005

I did the upgared as well, while I have my EB all apart. The upgraded motor and fan moved alot more out side of the box, but didn't seem to move as much when installed. I noticed the Chevy cage is shorter than the stock EB cage, so I moved it in a bit more to cover the inlet opening better. I haven't tried this new position yet, as I haven't finished the re-wiring part. Hopefully, I will be able to try it tonight........

ROKDWLR · Feb 14, 2005

brixter said:
I did this mod this weekend using the stock cage and ran into a problem , it was to long and hit the back of the heater box . So I went back to the parts store and got the chevy cage , but after putting it all together it was the same length as it was with the stock cage ???

Anyway I ended up cutting the back or center of the box a little bit (1/4")to allow the stock cage to fit . It works now , i am not real sure its much better which is kinda wierd cause when I tried it out side the box it was pushing a lot of air ?

How good are your heater core seals? That made a big difference on mine too.

ransil · Feb 14, 2005

Past_Miner said:
I had the same problem with the stock cage. I just couldn't get it to seat over the inlet involute inside the box. I went down to our local Carquest and had them pull every chevy cage they had until I found one that would work. I ended up using the standard duty cage, the AC/heavy duty cage also looked way too long, but bigger around. It may have worked if I had actually tried it. Either way I had to trim the box to get the cage in so I just used the shorter cage so I wouldn't have to go back to the store again.

It wasn't quite as cheap as I was expecting, but it was well worth it. Great upgrade.

I tried the heavy duty cage it would not fit.

kwspony · Feb 14, 2005

I suppose you could make a spacer to put between the motor and box. That way the cage won't hit the box in the back.

kwspony · Feb 20, 2005

I believe these motors have 3 speeds in the chevy's. Has anyone looked for a 3 speed switch yet?

Fathom · Feb 20, 2005

kwspony said:
I believe these motors have 3 speeds in the chevy's. Has anyone looked for a 3 speed switch yet?

The motor itself only has 1 wire. So the speed depends on how much power it gets.

The 2 speeds we get is:
1 straight through to the motor (High Speed)
2 pass through the "resister" mounted on the back of the housng (Low Speed)

SO to get another speed you would have to do some re-wiring and add another (diffent size) resister.

Or a potentiometer to make it variable speed ;D

Fathom

68ford · Feb 20, 2005

mine only has one wire going to the motor. i think after the resister, the 2 wires join and go into the motor if i remember corectly. if so cant you just rewire it the using the 1 wire going to the motor?

68ford · Feb 20, 2005

nevermind you talking about a third speed i think?

Past_Miner · Feb 20, 2005

cracker said:
I did the upgared as well, while I have my EB all apart. The upgraded motor and fan moved alot more out side of the box, but didn't seem to move as much when installed. I noticed the Chevy cage is shorter than the stock EB cage, so I moved it in a bit more to cover the inlet opening better. I haven't tried this new position yet, as I haven't finished the re-wiring part. Hopefully, I will be able to try it tonight........

I ended up shimming the cage about 1/2" off of the motor too. I basically went as far as I could go and still get the set screw to land on the flat of the shaft. It helped a lot, less recirculation into the inlet.

Daddy4zack · Feb 20, 2005

can this upgrade be done with the box in the cab or is it just easier to remove it all and do it..

Fathom · Feb 20, 2005

Daddy4zack said:
can this upgrade be done with the box in the cab or is it just easier to remove it all and do it..

I removed it, it was easy....I took the opertunity to rebuild/paint the box

Some install it while it is inside the Dash, their complaint was crampt conditions and dust everywhere.

Mark · Feb 20, 2005

It can be done with the heater box still installed, to do it that way or remove it, as far as difficulty, I think it's a wash. Either way not bad.
If you pull it, might as well replace the seals and maybe the heater core also.

68ford · Feb 20, 2005

while on the subject of removing the heater box, you guys have any tips on re-installing the cable on the back of it? i think it controls wether or not the air blows through the core? i didnt bother to hook it up last time just used a zip tie to keep it in the position so the air would blow through the core and get hot. ?:?

70 sport WA · Feb 20, 2005

68ford said:
while on the subject of removing the heater box, you guys have any tips on re-installing the cable on the back of it? ?:?

I will be tackling that tomorrow...for some reason, I think it might be a bit challenging...lots of wires and crap to get my fat hands into under the dash.

Anyway, my heater core gave up the ghost last week. I took the box out and replaced the core. Box goes back in tomorrow. There are two cables that connect in the back...one for the fan/heat switch and one for the defrost.

At the end of each cable is a looped end that connects to the crank arms (the rod-like things that control the flaps that direct air out of the box.) BUT, there is a bracket that comes off the box an inch or so near each of the crank arms...the cable passes over the bracket and is sandwiched between the bracket and a small tab. Gotta have that tab. A small screw holds the tab on the bracket (and thus holds or guides the cable in place.)

If none of this makes sense, I'll take pictures tomorrow and post. ;D

Dan

Heater Motor Upgrade

Bronco Guru

Bronco Klutz

Sr. Member

Sr. Member

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Sr. Member

Bronco Guru

Bronco Klutz

Bronco Guru

Sr. Member

Similar threads