Ac Blower Motor Upgrade

[bartgillam]

First off my AC works fine. I do not need to check the "in cabin air filter" or the actuator. I literally just want more air than stock to blow. Is it possible to upgrade the stock blower motor. I have googled the hell out of this but cannot seem to find anything leading me to believe it is a stupid idea but figured i would give it a shot and ask here. Thanks in advance for any help/suggestion.

 

[Bobmbx]

I haven't heard of such a thing, but if you could find the CFM output specs of the OEM blower, then shop around for one that has a bigger number. It would also have to fit.

 

[J_C]

Do you have the manual or automatic climate control? In theory you could build or rework one of those modules to supply the fan with higher voltage, using the existing fan.

It would run hotter and wear out faster but that's the catch with any higher RPM fan in the same space available for it.

Anyway the blower motor resistor pack was marginal already, prone to fail within the life of the vehicle and so is the automatic climate control transistor pack, so you'd probably need a control box mounted somewhere else with its own fan to cool it. THIS WOULD BE THE CASE WITH ANY FAN USING HIGHER CURRENT. The higher airflow rate "might" cool those better, but I'm guessing that there will be a larger control module heat increase than airflow increase because the rest of the system (air passages) remains the same.

The other route is you just source a higher RPM motor with the same shaft diameter, and it need not be remotely related to explorers or automotive use at all, just a DC fan with a bit higher RPM that's not so long that it doesn't fit in the available space and with tapped holes to mount it, then you cut the old one off the bracket and bolt the new one on, cannibalizing the connector to put on the new fan or buy a new connector if you can source it, or find any random mating pair of connectors at an electronics supply house and put the male end on the OEM wiring to replace the OEM connector.

Frankly I don't think it will help much in summer since higher airflow would be warmer, but in winter the heater is a smaller % of total engine heat so you'd see more difference then, but S. Carolina doesn't get cold enough to need it.

 

[bartgillam]

I see..well then might be a pointless expedition to trek on..I just wanted that hurricane of wind heh..i imagine i will just leave it be but i think ill take it all apart and clean it all and make sure the actuators fully open and find this in cabin air filter i keep hearing about see if i can squeeze some more airflow out of the stock fan. If the task is not terribly hard i might just replace the stock fan with another as it is 18 years old and probably not spinning as fast as it once did even though the airflow seems the same i could just be used to it.

 

[J_C]

I was under the impression that it was only 3rd or 4th gen Explorers and thereafter that had a cabin air filter. Until the fan exhibits definite signs of a problem, it's not likely to drop much in RPM except if it has a filter that's clogging up.

That doesn't mean that there isn't any possible variation in RPM between one aftermarket fan and another but from those I've seen, most if not all didn't have RPM listed.

One thing I forgot to mention is that if you have the automatic climate control there is possibly another option for a "little" higher RPM and airflow. With the automatic climate control the control module takes 12V (actually 14.something volts with engine running), passes that across a transistor for speed control, then to the motor. Passing across the transistor incurs a voltage drop called the forward voltage.

If you were to install a circuit with a switch and two wires going from the collector to the emitter of the transistor (2 pins on the firewall speed control module), then when you flipped the switch the fan would run at 1 to 2 volts higher. This is only theory, I do not have the automatic climate control on mine and assume the climate control head unit is always powering the fan through the firewall module, not already shorting it out of the circuit with a relay on highest fan setting.

However this brings up an interesting question. Does that mean the fastest the fan can spin on an automatic climate control system is slower than on the manual system? If the former I suggested is true and both use the same fan part # which they do AFAIK, then it would run at lower RPM on its highest fan speed setting due to the transistor module voltage drop.