Long story short, i have not been able to work on my poor old 1992 B250 van as it has been inaccessable to me for over a year now. But I finally have it back and I am able to pick up where I left off, though my mechanical skills are still as minimal as they were before!

Anyhow I am still having this issue i posted about in late 2019 with the blower fan only making a trickle of air flow out the vents. i hear and feel the blower running, and it is hot or cold as it should be, but air just barely trickles out the vents. adjusting the fan speed seems to make no difference, either in terms of the sound the blower makes, or the air flow. when i adjust the vent position it seems to come out the appropriate vents, and i hear the dampers moving, but same very low air flow.

I have replaced the blower fan (tyc 700102) and the blower motor resistor (standard motor products ru-480) but this has not helped.

perhaps i need a blower motor relay? can someone suggest a part number to buy at autozone or rockauto or amazon?

could the internal duct work be blocked with leaves or gunk or something? how do I get in there to clean those out?

any other suggestions to try or check to diagnose this?

thanks!

 

There are several things that could cause low air flow. The two that come to mind are, A, the blend door isn't moving. Maybe something simple like an actuator rod fell off. These are usually held on with plastic clips that get old, brittle and break. If you feel air blowing around inside the dash though, you may have a damaged air hose. If a rodent got in there and nested, you could be partially plugged and the hose might be gnawed through.

 

Remove the motor and use it's mounting space as an access point to inspect inside the housing for debris, use mirrors if it helps or stick a phone in there and take a bunch of pictures. Also make sure the motor is spinning in the correct direction, I've seen replacements wound in the wrong direction which requires the motor leads to be reversed.