19 replies to this topic

[lisab]

i need help!! our ac is not working.  when you turn it on  no air comes out but the outside unit works.  my husband took the blower off and checked to see if he could get readings. according to him and his buddies the blower motor is fine but still no air.  we changed the thermostat and no help.  thanks for any suggestions

[Samurai Appliance Repair Man]

[user=12917]lisab[/user] wrote:

according to him and his buddies the blower motor is fine but still no air. 

How did they determine the the blower motor is OK?

[Rrey199]

 Does the blower come on when the outdoor unit starts?

Some causes of the blower not coming on:

Bad Blower motor

Bad blower motor run capacitor

bad blower motor relay

bad thermostat

Broken t-stat wire

[lisab]

we bought a new blower motor, capacitor and new relay switch thingy.   we hooked everything back up  and we have very little air coming out of vents.  any suggestions as to why?  thanks

[hvacdrd]

Proceed in this order

1 - verify that the blower is running the correct direction.

2 - remove the blower door (may need to bypass the  door switch for unit to run) - if air flow resumes to normal then the problem is a dirty filter or obstructed return air duct or intake grille.

3 - blocked evaporator coil  (or secondary heat exchanger if 90%+ furnace) due to poor air filter maintenance. This is the fun one, requires some disassembly of the system to clean.

what type of system is it? upflow furnace with a/c,  downflow w/ a/c,  modular home, packaged unit,  a/c air handler, etc...

[lisab]

its a coleman mobile home unit. 

[lisab]

dont laugh  but how do you check the blower direction.  keep in my mind i know nothing about anything mechanical lol.  also is there anywhere online that has diagrams of the wiring? 

[hvacdrd]

A picture is in order...

Attached Files

•  blower.bmp   30.44K   45 downloads

[hvacdrd]

Missed the Coleman info...Is the blower mounted at the top of the furnace and is there a square panel at the bottom?

[lisab]

yes it is and yes there is

[hvacdrd]

Remove the bottom panel and you will soon discover why there is no air flow. I suspect what you will see looks like a dirty filter but is in fact the A-coil. Access might be tough if it has a gas line run in front of it. Peel back a corner if need be and tell me what you see...

[lisab]

ok i think i am confused.  the squirell cage sits right on top of the heater thing.  i dont see any filter other than the one that goes on top right above the coil and the one that attaches to the door.   hubby says there is no filter.  not too sound like i have no faith in hubby but well  some can and some cant lol.

[hvacdrd]

I'm not looking for the filter (the lack of one is why you have no air) - remove both cover panels- one for access to the blower the other for the burner compartment. At the bottom of this compartment there is a square panel, one insulated line, one small copper line and one plastic drain at the bottom. It is this panel to which I refer. Inside you will find the A-coil...try again. Usually there are 8-10 phillips head screws holding this panel in place.

Here is a crude picture...

Attached Files

•  blower.bmp   30.44K   43 downloads

[lisab]

ok the blower is spinning the wrong way.  how do you fix that.  on the heater panel thing  does it matter that our system is electric?

 

[lisab]

im sorry i just saw the diagram for the panel.  that is not the way our system is set up.     from top to bottom is the coil, the blower and then heater.  all of the electric wires and such are  in front of the heating stuff. 

[AccApp]

Most replacement motors are reversible and will include wiring directions for correct rotation. The wiring diagram/instructions may be on the motor's label.

[lisab]

the motor came with a little chart thing.  not clear directions on where the wires go at all.  the motor we replaced was a 4 speed and we went to a 3 speed so of course it doesnt wire up the same.  is there any diagrams for wiring online?

[Rrey199]

 Thought I'd add my $.02. Where the wires come out of the motor, is there four short wires with plugs. If it's reversible there should be two pairs plugged into each other. By changing which ones are connected, you can reverse the motor. (Example: The yellow and purple together, and the orange and brown together. )If not, sometimes there are holes drilled so you can mount the motor on the opposite side of the blower housing. This will reverse the rotation of the blower wheel.

[Samurai Appliance Repair Man]

[user=12917]lisab[/user] wrote:

the motor came with a little chart thing.  not clear directions on where the wires go at all.

Post a copy of what they sent you.  If you can't do that, then fax it to me at 775-416-4449 and note on your fax which topic it's for.

[Dan Webster]

wow the thought that I had was when they replaced the motor did they take the blower assembly apart and really clean out the blower wheel good? If so then I suspect they prob didnt check the motor to see if it was a running in the right direction . you can do this by putting 115 volts to the common wire and the black wire for a second . if you aint sure what the common wire is then a diagram is located on the side of the motor . what was the brand of replacement motor used if I may ask?