I know this has been discussed before, but I though it might be a good idea to pool information toghether in one post. The heater and AC blower in our trucks is nothing compared to the ones in more modern vehicles. Has anyone discovered an alternative that works better? I have a few ideas, and I'd like to see what ya'll think about them. Someone may have allready tried these, so putting this info out there may help someoone.

1. A bigger motor attatched to the same blower wheel?

2. An aftermarket solution? ( haven't found anything)

3. A bigger Ford application? I was think a Ford conversion van might have a fan with more CFM but still mount the same or similar.

4. Use a relay and power the blower directly off the battery (more volts= faster fan)

5. Install an additional "helper fan" somewhere in the system to boost airflow.

6. Install an additional evap and blower in the rear.......maybe if you live in Death Valley, otherwise probably way too much work.

 

I would like info on this subject too...

 

Yeah, my AC gets as cold as ice, it just doesn't blow hard enough to get it into the rear area. I think there might be some hope of getting a higher CFM fan from a larger Ford. Even if it takes a little bit of modification, I think it would be worth it. Even some kind of small booster fan installed under the dash might help. You could wire it so that it would only come on with the "high" setting. I'm also wondering about switching the motor out for a bigger one, and reusing the same blower wheel. I'm sure someone out there has allready eliminated a few of these possibilities, but I think we can figure out something toghether.

 

I think a newer model fan would be easier to put in good working order.

 

Truth be told, the squirrel cage (fan blade) itself has a lot to do with the volume of air actually being moved. Newer squirrel cages have better flow capacity and finding one of similar diameter to the OEM unit could provide better air flow without a lot of electrical modifications. Guess I should go grab one of the extra ones from the garage and get a diameter measurement. Make sure the cowl intake vents are clear as well. If the blower can't pull enough air in, it can't push enough out.

 

Good point Grey, a better wheel might be all it needs. If there is enough clearance, a deeper wheel might provide more surface area, and thus more air flow. I know alot of people have asked about this before, I would love to come up with something that we could add to the FAQs or something.

 

Ok folks, OEM blower squirrel cage (blade) is made of plastic/nylon and appears to be (as taken from the cowl in a 1992 model) 3 1/4" deep by 5 3/4" in diameter. The housing doesn't leave any room for going any larger in diameter without cutting the hole larger. The bolt holes and guide pins only have about a 1/4" of material between them and the edge of the hole for the squirrel cage so cutting much more material away for a larger diameter cage would necessitate drilling new holes in the motor flange. The motor flange and plastic housing have enough diameter that you could feasibly drill new holes on a 1/2" larger diameter circle than the existing holes. This would increase the bolt pattern circle diameter to a full 7" up from the 6 1/2" of an OEM motor flange. This would allow for a squirrel cage closer to 6 1/4" - 6 1/2" in diameter rather than the 5 3/4" maximum diameter of the OEM cage. A larger diameter cage would no doubt increase air volume and the number of blades in the cage.

The depth of the housing is a full 1/2" deeper than the squirrel cage itself. While some space is needed for clearance and tolerance for a spinning cage, if you could find a 3 1/2"-3 3/14" depth squirrel cage of the proper diameter, you would effectively increase the volume of air moved by the blower.

The motor shaft is 1/4" in diameter.

I am off in search of feasible squirrel cages of slightly larger dimensions than OEM. I will post when/if I come up with any.

 

Greystreak touched on it, but I wanted to add that these trucks collect a lot of leaf debris in the blower housing and mice will make the issue worse. In fact this is a serious fire hazard since the blower motor resistor pack is also mounted in the blower housing on the inlet side of the evaporator (see bottom pic). Any search for increased flow should start with a thorough inspection and cleaning of the blower housing. Here is what I found in my truck when I was looking for air flow

 

I use to have a 79' Vette with the same problem. I got a fan that was about 1" deeper. I had to make a spacer for it to mount. You would have thought the extra air was blowing against the spacer. It did work better. I'm going to look in my housing, that post above is hard to believe. But then again, our trucks are 20 years old.

 

I just checked my housing. No leaves. (I remembered that I had the whole system replaced a few years back) This is eazy to check. The four screws have 1/4" hex heads that fit a screwdriver with the bit removed. One thing I noticed was a small rubber tube that goes from the air box to the motor. It is probubly to cool the motor. My tube was not on the air box so not only was it not cooling the motor, air was leaking out of the box and the motor.

 

I wonder if the supercrew, 4 door model trucks of the same era had a higher CFM setup. It would be nice if some company manufactured a spacer that would bolt to the shroud, and move the fan further out. That way you could use a much deeper wheel. Install a relay to get power direct from the battery, and it might rival the systems in newer vehicles.

 

Hey Massey, i saw in your sig you have a Mean Green alternator, is it better than going with the 3g?.

 

This got me thinking...about 25 years ago my favorite Ford mechanic specialized in A/C. I just now remembered his comment to always recirculate the air to keep the coils from getting as dirty. Now I'm wondering if a coil cleaner like used in our home A/C is possible to use? The condenser is fairly easy in front of the radiator. However, the evaporator is hidden, could be dirty and restricting air flow. Can it be cleaned?

Thanks for suggesting this thread. After installing a severe duty radiator fan I still want more cooling.

 

Unless the wires are undersize, running straight from the battery is not going to make the fan run faster. If the wires were undersize, they would be getting hot. So I dont think thats the way to go.

 

I love the mean green alternator, it can handle anything you throw at it. If your willing to throw 300 bucks out there for an alternator, I say go for it. The only modification required is a larger line to the battery, and a smaller serpentine belt. You can tell the quality of the unit when you pick it up, it ways easily twice as much as the stock unit, although its about the same size.