Vents output low in Heater/AC

[SHOfun 93]

I have noticed that my output on the vents in my heater has reduced. Is there a filter or something that needs cleaning to help boost this back up? Thanks.

 

[DHMag]

Jeremy Hohn:
I have noticed that my output on the vents in my heater has reduced. Is there a filter or something that needs cleaning to help boost this back up? Thanks.

heya Jerms, long time no see....it might be the blend door malfunctioning. when selecting the different positions, you should hear a slight hiss along with a light thump *blend door closing/opening*. im not sure what to specifically look for when checking the blend door though. if there is a constant hiss, means youve split a line...

 

[sdpatt]

Or the evaporator is plugged with dust or paper. When I took my ducting apart (granted, that was at about 255,000 miles), the evaporator fins were about half covered with the ages of dust that had been passed through them. When I vacuumed and wiped them clean, it felt like a new fan motor on "turbo." How does the fan sound? Is it spinning fast? That may be due to flow obstructions like the ones mentioned above or the blend door problem as discussed previously

 

[projectSHO89]

My slower than normal speed was due to corroded contacts in the blower motor switch. Replacement switch from a boneyard SLO fixed it.

This was confirmed by measuring the voltage at the motor with a meter.

Steve