Fan motor

[billj770]

Has anyone replaced the ac/heater fan motor on a 390bh? I have a blade broke off and it vibe rates very bad on high. This is the truck ac/heater not the over head heat pump.

[VinceU]

Is that a propeller or squirrel cage rotor? Dash vent normally cage type.

[billj770]

I assume it is a cage, either way getting to it looks to be difficult.

[VinceU]

Originally Posted by billj770

I assume it is a cage, either way getting to it looks to be difficult.

If you can get to it, its easy to remove the impeller by opening casing on suction side (opposite side from motor drive. Sometimes a screen covers the opening or a large corugated hose. Remove hose and cover plate. The impeller could be bolted on the shaft or just spring clips.
If you can get it off, locate damge blade/blades. clean up edges where damaged. On exact opposite side of this rotor cut the same blades out cleanly using shears or Dremel cut off tool. This will put the impeller close to balance and will last until you ID and purchase new.
Most likely this is not a chassis supplied part but an HVAC vendor supply. FR can ID and supply or if you can find the A/C builder probably would be quicker.
Not knowing who built it can be aluminum alloy or plastic fan. Really not a big job.
Oh yes it may be the hub to shaft fit has failed,npt blades, also easy to fix with epoxy or shim depending on the failure.

[billj770]

Thanks. My concern is fighting the dash, looks like a lot of work.

[VinceU]

Originally Posted by billj770

Thanks. My concern is fighting the dash, looks like a lot of work.

Understand problem, suggest slow speed operation till repaired, might last longer.

[billj770]

Originally Posted by VinceU

Understand problem, suggest slow speed operation till repaired, might last longer.

Replaced the fan cage today. The dash has to be almost removed. Not easy. The fan and motor assembly are from a late 90's Chevy Suburban works great. Got it from NAPA.

On another note. My step quit working today, I found the 4 pin connector was dirty and making poor contact. Pulled it apart and cleaned it, works like a charm.

[VinceU]

Originally Posted by billj770

Replaced the fan cage today. The dash has to be almost removed. Not easy. The fan and motor assembly are from a late 90's Chevy Suburban works great. Got it from NAPA.

On another note. My step quit working today, I found the 4 pin connector was dirty and making poor contact. Pulled it apart and cleaned it, works like a charm.

Sounds great, saved yourself enough for another trip!