# Blower Motor Wiring reversed?



## HVACMac (Aug 13, 2011)

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.

My question:

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? 
TIA,
Ron


----------



## biggles (Jan 1, 2008)

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..:wink: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:whistling2:


----------



## JJboy (Oct 12, 2010)

High speed on colling model 
Med high speed or Med speed to heating mode


----------



## HVACMac (Aug 13, 2011)

> if not the heat and cool fan relays wires(Black/RED) within the furnace are backwards..:wink: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:whistling2:


The pic posted shows two relays. I see a transformer, next to it is a small brown relay and above it to the right is a large aluminum Honeywell relay? Your thoughts?
http://imgs.inkfrog.com/pix/msmikee/relays.jpg


----------



## JJboy (Oct 12, 2010)

Black wire should be connected in high speed on control board. Check also if A-coil is clean. Filter is clean. 

Could be low on refrigerant. But you need hook up the gauges to check this


----------



## HVACMac (Aug 13, 2011)

JJboy said:


> Black wire should be connected in high speed on control board. Check also if A-coil is clean. Filter is clean.
> 
> Could be low on refrigerant. But you need hook up the gauges to check this


Forgot to say, Freon is fine. All filters are clean. A-Coil has been is cleaned. As to "black wire to control board" thats a big unknown to me, Have no idea where to even look. 


Ron


----------



## JJboy (Oct 12, 2010)

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.


----------



## HVACMac (Aug 13, 2011)

JJboy said:


> 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


----------



## JJboy (Oct 12, 2010)

I'm in Texas. I know it's hard to keep inside the house cold when outdoor temp is 105-110. I think your AC is running ok. You have to leave your AC running all night to remove all the heat. :thumbsup:


----------



## HVACMac (Aug 13, 2011)

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


----------



## JJboy (Oct 12, 2010)

Assuming that AC is okay. It's just a sensation that air is not flowing properly during hot days. I bet this ends during normal days. This is the same thing when AC is low of refrigerant.


----------



## HVACMac (Aug 13, 2011)

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?


----------



## Master of Cold (Aug 7, 2011)

I guess you missed post #2..


----------



## beenthere (Oct 11, 2008)

What size is the A/C, and what size is the return air grille. have you removed the air filter and ran it to see if it blows more air out.


----------



## JJboy (Oct 12, 2010)

What I am trying to say that your problem is not AC. The problem is more serious, insulation, load calculation, ducts calculation.

The blower motor is already setup in high speed in cooling mode ( motor black wire )


----------



## HVACMac (Aug 13, 2011)

Master of Cold said:


> I guess you missed post #2..


Could have sworn I answered. Yes, I did follow suggestion to cap blue, replace w/ red. Nothing changed. As far seeing if wires are switched on relays, I posted pics. But, I think this is what separates the men from the boys. Might be a bit too complicated for this newbie.


----------



## HVACMac (Aug 13, 2011)

beenthere said:


> What size is the A/C, and what size is the return air grille. have you removed the air filter and ran it to see if it blows more air out.


2.5 tons ruud, air grille= 18"x12", both air filter removed, no change.


----------



## HVACMac (Aug 13, 2011)

JJboy said:


> What I am trying to say that your problem is not AC. The problem is more serious, insulation, load calculation, ducts calculation.
> 
> The blower motor is already setup in high speed in cooling mode ( motor black wire )


That may well be the case all the above, except I still do not understand why the volume of air coming out is so minimal.


----------



## Master of Cold (Aug 7, 2011)

What jj is saying is that when the air temp coming out of the vents is close to the same as the room, the volume of air does not feel like it does when it is 20 degrees colder. The temperature drop across your skin is a stronger sensation than the airflow.

The blower motor may well be having issues. You could swap the red and black wires and see if anything changes.


----------



## beenthere (Oct 11, 2008)

HVACMac said:


> 2.5 tons ruud, air grille= 18"x12", both air filter removed, no change.



Thats too small for a 2.5 ton system. Its only good for about 1 ton.


----------



## Master of Cold (Aug 7, 2011)

beenthere said:


> Thats too small for a 2.5 ton system. Its only good for about 1 ton.


I see you have never been to Florida


----------



## beenthere (Oct 11, 2008)

Master of Cold said:


> I see you have never been to Florida



LOL... Actually, I have been there. ROFL.


----------



## JJboy (Oct 12, 2010)

beenthere said:


> Thats too small for a 2.5 ton system. Its only good for about 1 ton.


How do you do this calculation? I thought 18"x12" would be good for 1300 CFM, 2.5 ton


----------



## HVACMac (Aug 13, 2011)

Master of Cold said:


> What jj is saying is that when the air temp coming out of the vents is close to the same as the room, the volume of air does not feel like it does when it is 20 degrees colder. The temperature drop across your skin is a stronger sensation than the airflow.
> 
> The blower motor may well be having issues. You could swap the red and black wires and see if anything changes.


 I do understand what jj is saying and agree to a certain point. Sensation is only part of the diagnosis. What I am failing to communicate is the actual airflow IS a wisp. I have these bright orange plastic 1/4" x 8" long streamers hanging from the bdrm registers. I can not only feel the lack of airflow I can see it too! Limp as a dish rag. I mean, you'd think hi speed blowing would stiffen these streamers straight out. :wink:


----------



## HVACMac (Aug 13, 2011)

beenthere said:


> Thats too small for a 2.5 ton system. Its only good for about 1 ton.


CORRECTION

Remeasured, duct is 15" dia. Covered by rectangular grill.


----------



## biggles (Jan 1, 2008)

that silver covered HONEYWELL is the fan/hi limit for the heating side...i got it ...:thumbup:....they wired the hi speed into the heat limiter and the low speed into that black relay.test this shut the stat off system and fan in auto...go down pull that silver cover and turn it clock wise and tell use what speed the fan comes on.like i said the ON/AUTO on the subbase is cooling fan control only:wink: the heat "high limit" and fan on/off are threw that silver limit control during the winter..the speed wires have to be backwards:yes:....are the round fins on the fan squirrel clean of dirt dust crap run your index finger along them


----------



## SKIP4661 (Dec 3, 2008)

Is that blower motor original, looking at the hp rating on the motor it might be a little light for 2.5 tons of air.


----------



## HVACMac (Aug 13, 2011)

biggles said:


> that silver covered HONEYWELL is the fan/hi limit for the heating side...i got it ...:thumbup:....they wired the hi speed into the heat limiter and the low speed into that black relay.test this shut the stat off system and fan in auto...go down pull that silver cover and turn it clock wise and tell use what speed the fan comes on.like i said the ON/AUTO on the subbase is cooling fan control only:wink: the heat "high limit" and fan on/off are threw that silver limit control during the winter..the speed wires have to be backwards:yes:....are the round fins on the fan squirrel clean of dirt dust crap run your index finger along them


Woohoo, thx biggles!! Glad the pics posted were of some use. I'll give it try, let's hope your idea works! I'll be right on it in the morn. 

Yes, one of the 1st things I did. Pulled the blower squirrel cage out and clean it. I also peeked into- top of the evaporator, looks generally clean.


----------



## HVACMac (Aug 13, 2011)

SKIP4661 said:


> Is that blower motor original, looking at the hp rating on the motor it might be a little light for 2.5 tons of air.


Have no idea, came w/ house ten yrs ago.


----------



## beenthere (Oct 11, 2008)

JJboy said:


> How do you do this calculation? I thought 18"x12" would be good for 1300 CFM, 2.5 ton


For a 300FPM velocity. L * W * 1.6 = CFM

A 12X20 Hart&Cooley #650 return filter grille is listed as 343 CFM at 300 FPM, 457 CFM at 400 FPM, 571 CFM at 500 FPM, 685 CFM at 600 FPM, and 800 CFM at 700 FPM.


A filter grille is not suppose to have air going through it at duct velocity.


----------



## HVACMac (Aug 13, 2011)

biggles said:


> that silver covered HONEYWELL is the fan/hi limit for the heating side...i got it ...:thumbup:....they wired the hi speed into the heat limiter and the low speed into that black relay.test this shut the stat off system and fan in auto...go down pull that silver cover and turn it clock wise and tell use what speed the fan comes on.like i said the ON/AUTO on the subbase is cooling fan control only:wink: the heat "high limit" and fan on/off are threw that silver limit control during the winter..the speed wires have to be backwards:yes:....are the round fins on the fan squirrel clean of dirt dust crap run your index finger along them


OK, Pulled the aluminum Honeywell cover off. See pic below. Ok, what settings/test am I shooting for? Also, per your instructions, on the thermostat I've turned it to "Off" and the Fan setting is on "Auto". Correct?


----------



## biggles (Jan 1, 2008)

turn that dial slowly till the fan comes on i think it should without a heat call from the board if not the test is aced...won't prove to me that your wired for HI speed in the heating mode...this Honeywell limiter is 100% for the heating side of the unit doesn't even have any stat connections ..this is why you can check the fan from the stat with fan ON in the heating mode the closure on those 2 red wires is fan ON as the dial heats up and the metal pig tail in the burner chamber expands and turns the dial to 150F


----------



## HVACMac (Aug 13, 2011)

biggles said:


> turn that dial slowly till the fan comes on i think it should without a heat call from the board if not the test is aced...won't prove to me that your wired for HI speed in the heating mode...this Honeywell limiter is 100% for the heating side of the unit doesn't even have any stat connections ..this is why you can check the fan from the stat with fan ON in the heating mode the closure on those 2 red wires is fan ON as the dial heats up and the metal pig tail in the burner chamber expands and turns the dial to 150F


I appreciate all the help you given and will try this out when I return. If the fan does turn on, what do I do next? Leave it as is, will it affect heating come winter?
TIA, Ron


----------



## biggles (Jan 1, 2008)

i need you to tell us if it is high speed when you turn that dial CW...should be LOW to LOW MED..but definitly different air amounts


----------



## HVACMac (Aug 13, 2011)

biggles said:


> i need you to tell us if it is high speed when you turn that dial CW...should be LOW to LOW MED..but definitly different air amounts


I was able finally able to do a quick test. (Btw, Yesterday, I discovered the downstairs A/C (a completely separate unit) blower motor died! I've got it on order soon to replace it.) 

I did the changes as you suggested above and no difference. Same amount of air moving out as indicated by the streamers attached to the vents.


----------



## biggles (Jan 1, 2008)

OK so the unit is wired for Lo speed in the heating side with that...so now you have 2 sepreated air handlers both with heating and cooling?????:huh:this is why contractors bang $$$$ homeowners you live in the house they don't


----------



## Master of Cold (Aug 7, 2011)

biggles said:


> OK so the unit is wired for Lo speed in the heating side with that...so now you have 2 sepreated air handlers both with heating and cooling?????:huh:this is why contractors bang $$$$ homeowners you live in the house they don't


I think he has two floors. 
Don't worry commercial gets banged far worse than homeowners.


----------



## HVACMac (Aug 13, 2011)

biggles said:


> OK so the unit is wired for Lo speed in the heating side with that...so now you have 2 sepreated air handlers both with heating and cooling?????:huh:this is why contractors bang $$$$ homeowners you live in the house they don't


It gets worse, two water heaters. Up/downstairs. Btw, Up stairs a/c unit is on it's last legs, nearly 20 yrs old, Ruud 2.5t. The other is 12 yr old rheem 3.5t. What's best, replace both w/ 6t unit?


----------



## newtech (Mar 21, 2009)

HVACMac said:


> It gets worse, two water heaters. Up/downstairs. Btw, Up stairs a/c unit is on it's last legs, nearly 20 yrs old, Ruud 2.5t. The other is 12 yr old rheem 3.5t. What's best, replace both w/ 6t unit?


I would stay with 2 separate units.. Did you check the duct work for leaks???

If you rotated the dial on the fan and limit switch, you may have messed up the sensing element, which it will need to be replaced. That is why is says DO NOT rotate on the dial..


----------



## HVACMac (Aug 13, 2011)

newtech said:


> I would stay with 2 separate units.. Did you check the duct work for leaks???
> 
> If you rotated the dial on the fan and limit switch, you may have messed up the sensing element, which it will need to be replaced. That is why is says DO NOT rotate on the dial..


Damn, I hope not! I saw that "caution" notice. I would think it wouldn't be so sensitive. AM hoping there should be some leeway. Will this, if damaged, show up only when heater is used? I don't want to burn my house down. I'll back-off on my DIY, until I hire qualified pro. Thank you for the input.


----------



## newtech (Mar 21, 2009)

HVACMac said:


> Damn, I hope not! I saw that "caution" notice. I would think it wouldn't be so sensitive. AM hoping there should be some leeway. Will this, if damaged, show up only when heater is used? I don't want to burn my house down. I'll back-off on my DIY, until I hire qualified pro. Thank you for the input.


I would have a pro check it out before the heating season and before you use the heat for the first time. The directions clearly state to hold the dial when adjusting the set points so it does not rotate.

It is a Fan and LIMIT control... I would be worried that the limit part of it got messed up... 

I would have advised you earlier, but, I saw it too late.


New


----------



## HVACMac (Aug 13, 2011)

newtech said:


> I would have a pro check it out before the heating season and before you use the heat for the first time. The directions clearly state to hold the dial when adjusting the set points so it does not rotate.
> 
> It is a Fan and LIMIT control... I would be worried that the limit part of it got messed up...
> 
> ...


Better late than never, I should have been a tad more patient. I didn't see anyone pop up with any caution and I failed to ask, (even though that question was right there at the tip of my finger tips.  I went ahead and turned. Ultimately, my fault. Like they say: DYODD!! A lesson has been served. Who knows, you may have saved me and my family from true misery and/or tragedy. THANK YOU!
Ron


----------



## biggles (Jan 1, 2008)

one short fan test on that dial isn't going to cause any damage to it :wink: if you turned it to trip the gas cycle to check the hi limit maybe..why you scaring this guy into checking his fire insurance....:furious:


----------



## newtech (Mar 21, 2009)

biggles said:


> why you scaring this guy into checking his fire insurance....:furious:


Because you gave him the wrong advise...

It doesn't matter if you turned it once or twice.. You are not supposed to..

Why would you advise someone to do it......:furious:

The install manual clearly states " DO NOT TURN THE DIAL " 

I guess you know better than the MFG of the part:no: it states not to rotate it:whistling2:


----------



## newtech (Mar 21, 2009)

biggles;709462one short fan test on that dial isn't going to cause any damage to it :wink: said:


> Are you willing to back up that statement .:wink:
> 
> If it fails


----------



## beenthere (Oct 11, 2008)

biggles said:


> one short fan test on that dial isn't going to cause any damage to it :wink: if you turned it to trip the gas cycle to check the hi limit maybe..why you scaring this guy into checking his fire insurance....:furious:



Gee, I hate to admit it. but, I rotated the dial on several hundred of them already. And none of them ever failed because I rotated them. Found a few that had bad contacts and wouldn't turn on the fan, or the limit contacts wouldn't open up, by testing it that way.


----------



## newtech (Mar 21, 2009)

beenthere said:


> Gee, I hate to admit it. but, I rotated the dial on several hundred of them already. And none of them ever failed because I rotated them. Found a few that had bad contacts and wouldn't turn on the fan, or the limit contacts wouldn't open up, by testing it that way.


"CAUTION
When adjusting the fan and limit set point levers
(Fig. 10), hold the scalepale dial to keep it from turning
and straining the sensing element.
Move each indicator lever to the control point
recommended by the burner or furnace manufacturer.
Use gentle finger pressure
CHECKOUT
When installation is complete, disconnect the fan
motor circuit . Turn on power and set
thermostat to call for heat. Burner should come on and
limit controller should shut burner off when plenum
temperature reaches the limit set point. Turn off power,
recconnect the fan switch, turn on power and again set
thermostat to call for heat. Fan should come on when
plenum temperature has reached fan-on setting."


----------



## beenthere (Oct 11, 2008)

yep. Why worry about a cheap fan limit switch, when we can over heat the expensive heat exchanger.


----------



## newtech (Mar 21, 2009)

beenthere said:


> yep. Why worry about a cheap fan limit switch, when we can over heat the expensive heat exchanger.


So what you are you saying???

1. The fan and limit is cheap. So if you turn the dial and screw it up, no big deal to change it.
Or

2. If you rotate the dial and it gets out of calibration you could over heat the He!! out of the unit.

If there " WAS " a small crack in the HX, and you were doing a PM on it and just rotated the dial to see if the high limit was working you probably would have not found it.



Most of the HX that used the fan and limit's were pretty tough, so to trip them on the limit without the fan on start up was normal practice to make sure that they worked. We even had to have a temp probe mounted to verify the cut out temp.











There is a check out procedure for just about every product sold in the HVAC world:yes:

If you want to vary from this, that is your business.



Just my opinion


----------



## newtech (Mar 21, 2009)

beenthere said:


> Gee, I hate to admit it. but, I rotated the dial on several hundred of them already. And none of them ever failed because I rotated them. Found a few that had bad contacts and wouldn't turn on the fan, or the limit contacts wouldn't open up, by testing it that way.



Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. DIYChatroom.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any home improvement task!


----------



## beenthere (Oct 11, 2008)

newtech said:


> So what you are you saying???
> 
> 1. The fan and limit is cheap. So if you turn the dial and screw it up, no big deal to change it.
> Or
> ...



You ain't gonna harm a Honeywell L4064B fan limit by rotating its dial. Unless its already worn out.


----------



## Master of Cold (Aug 7, 2011)

newtech said:


> Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. DIYChatroom.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any home improvement task!


Hey! Who let the lawyer in here?


----------



## HVACMac (Aug 13, 2011)

beenthere said:


> You ain't gonna harm a Honeywell L4064B fan limit by rotating its dial. Unless its already worn out.


How does one know or tell if its "worn-out"?


----------



## beenthere (Oct 11, 2008)

First, if it doesn't turn the fan off or on, its worn out. Next, if it doesn't open up the limit contacts its worn out.

I do rotate it to see if the limit opens. I check by running the burner, if it will bring the fan on an d turn it back off. And compare it to my temp probes.


----------



## newtech (Mar 21, 2009)

beenthere said:


> You ain't gonna harm a Honeywell L4064B fan limit by rotating its dial. Unless its already worn out.


Thats not a L4064B in the pic...


----------



## beenthere (Oct 11, 2008)

newtech said:


> Thats not a L4064B in the pic...


Which pic. And what is it then.


----------



## newtech (Mar 21, 2009)

beenthere said:


> Which pic. And what is it then.



Post #31

The L4064B has a manual switch to provide
continuous fan operation.


----------



## beenthere (Oct 11, 2008)

newtech said:


> Post #31
> 
> The L4064B has a manual switch to provide
> continuous fan operation.


LOL... Your right. L4064 B's, D's, F's, R's and W's have the manual fan on switch.

L4064 A's, J's, T's, and Y's don't. But its still an L4064 fan limit control/switch.

T's, W's, and Y's have a built in heater to assist in bringing on the fan.


----------



## newtech (Mar 21, 2009)

beenthere said:


> LOL... Your right. L4064 B's, D's, F's, R's and W's have the manual fan on switch.
> 
> L4064 A's, J's, T's, and Y's don't. But its still an L4064 fan limit control/switch.
> 
> T's, W's, and Y's have a built in heater to assist in bringing on the fan.


We must have the same manual:thumbsup:

My only concern is, how he kept the fan running to check the air flow...

Did he turn the dial and lock it in position, hold it for any length of time while someone else checked the air flow.

Just some questions that I would be concerned with.

And I will still state that it needs to be checked out before the heating season. It is a 20yr old unit and if it is the original fan and limit, who knows what might happen... jmo


----------



## beenthere (Oct 11, 2008)

maybe he used the fan on setting at the stat.

All 20 year old furnaces need checked annually. They are at the end of their expected life span.


----------

