With the triple digits 100-115 temps out here in Oklahoma I've found the upstairs A/C cannot keep up with the heat. Herein lies problem as I see it. I think the blower motor is wired incorrectly. In the winter the air blowing out of the registers are far greater than in the summer. Its just a trickle in the summer. Not enough air is moving to adequately cool the upstairs. My downstairs unit, (separate A/C heating unit- top from bottom) blows a great amount of air. Filters have been cleaned, same goes for condensers fins outside-All cleaned.
Below are photos.
Here is what I have:
Three wires coming in and five wires coming out of the Blower motor. Here is how it's connected, also see pics below.
Three wires / Five wires (blower motor)
Red ------- Blue
Black ------ Black
White ----- White
____ ------ Red Capped
____ ------ Green connected to housing
On the blower motor is a label showing the wiring diagram.
Another label is found on the shroud or blower motor housing.
The 2nd photo shows how it is connected.
Does this connection confirm the blower motor is connected improperly, esp for summer use? In other words, as connected is this why in the summer the A/C air discharge is so light? Naturally, if it is incorrectly connected how do I then correct it?
Looking fwd to your help?
Last edited by HVACMac; 08-13-2011 at 04:24 PM.
Reason: image probs
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cap the blue(that was connected to that power in red) and connect the 2 reds together RED is LOW for Heat............ Black is HI for cooling.now to see if the fan runs in hi speed shut the stat and only switch the FAN to ON should have the hi fan blowing...if not the heat and cool fan relays wires(Black/RED) within the furnace are backwards..you can't check LO fan with the heat from the stat because it cycles thru a time delayon that board in the furnace in the heating season not like the stat as FAN/ON from the subbase...lets hear back
if not the heat and cool fan relays wires(Black/RED) within the furnace are backwards..you can't check LO fan with the heat from the stat because it cycles thru a time delayon that board in the furnace in the heating season not like the stat as FAN/ON from the subbase...lets hear back
To make sure your AC is running ok, you need to get the temp at the return and just after the a-coil. If the temp difference is under 15 you have some problem. If not, It's insulation problem.
Hey Jj, thx. I think that is way beyound my limited expertise. A month or so ago a HVAC man did check the freon levels and found them to be fine. He check temps using his gauges. But, not sure what he was referencing. Ron
I hear that! TX was nearly as hot as us.
The downstairs unit really can keep the first floor cold AND it really can blow air. While upstairs the A/C has to contend with the attic heat and the evaporator/Furnace/ducts are all in the attic too! So its hot all around. Not surprised its struggling with 105+ degrees. Worse, temps are even hotter in the attic.
But, what concerns me, is the low volume of air coming out of the registers. Doesn't make sense to me and is why Im posting hoping to find an answer or least some direction before I call the A/C man. Ron
Exactly. Where Iam stumped is the volume of air I am NOT getting as compared to downstairs. Downstairs air rushes out from every register with great volume. Upstairs is only a whisper. I' am wondering maybe a faster RPM motor is needed?