Heater Air Flow is always low

[FordFETruck]

Never thought a whole lot about it, but the heater fan output on my truck kind of sucks too. Heat only, no A/c or vacuum lines on mine. All 3 motor speeds work, heater box is free of debris, so is the cowl. Seems to have good fan speed but the defrost output is about half of any other vehicle I've had. Didn't find any holes in the hoses to the defrost vents. Do these trucks just have poor blower output in general?

[grumpin]

From my experience I would say yes, they do not blow very well.

I replaced the fan motor on the 86 I used to have and didn't notice an improvement.

It did the job though. Maybe they are more efficient, enough flow with less noise!

[Gary Lewis]

Yes, my opinion is that the flow is poor, even with a new motor and relays in the wiring to ensure there's little voltage loss.  I even asked a company that rebuilds motors if they could rewire the motor for more power, and they said they could - for $2000.  I guess I'll live with it.  

[ArdWrknTrk]

Still doesn't explain why it has one speed and won't shut off.  
Or why it hasn't defaulted to defrost.

I'd look at the motor or resistor plug for melted wires that may be shorting to ground.