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  1. #1


    I've spent several hours trying to figure out definatively what component is keeping my air handler blower motor from starting. To start, the system worked fine until we turned it off temporarily last night to watch a movie in peace, as the air handler closet is directly behind the sofa. My air handler is a RUUD, probably early '80s, original to the house. I changed the relay, as this has been a past culprit, but not this time. I then removed the blower motor and hooked up 220V to its two leads and the motor worked great. I'm now thinking it is either the motor's capacitor, although the capacitor shows no visible signs of demise, or the transformer. Something that has me perplexed is that with the thermostat turned to "off" and "auto" I show 125 volts/6 amps at both of the leads to the blower motor. If I turn the thermostat's motor control to "on" or the switch to "heat" or "cold" I have the same readings. When I ran the motor off of another 220V source I checked the readings and they were the same- 125V/6A at each lead. This has me wondering how the motor gets a signal to actually come on when the thermostat is turned to "on" or "cool/heat". There are no other wires running to the motor. One of the leads (black) goes from the relay to the motor, and the other (orange) runs straight from one of the bus fuses to the motor. Magic maybe? Also, the condensor is coming on when turned to "cool", so maybe this will rule out some possible culprits. Oh yeah, I also connected a new thermostat I had left over from a house I built with the thought that possibly there was a malfunction in the current thermostat, but that made no difference. I know this is a long post, but I like to be concisely descriptive to make up for my ignorance.

  2. #2

    6 amps ?

    Thats a lot of amps for a motor thats not running. I think your looking for 220/240 across both leads. You may want to get a plummer to straighten that **it out.

  3. #3
    Join Date
    Jun 2003
    I know this isn't what you want to hear.....but make the phonecall to a qualified hvac company, before you spend more $$$ in parts than the call costs. You've already changed a contactor to no effect......what's next,capacitor? Then t-stat? then.......
    If everything was always done "by the book"....the book would never change.

  4. #4
    Join Date
    Jan 2005
    Littleton, CO
    I have to agree with smokin68 on this one.

  5. #5
    I was sold the wrong relay by the "professional" at the A/C distributor. The relay I was given looked identical to the relay from the unit, but the relay I was given has a 208/240V coil and my unit has a 24V coil. That's what I get for not double checking every detail of what I was sold before leaving the store. This is what really irritates me. I am chastised by the people who left me replies to my query for acting resourcefully and taking on a task that I know I am capable of performing. The initial relay that I thought was the problem was in fact the problem. The salesman made a simple mistake and that is understandable. But the fact that the individuals who left me sarcastic, unhelpful replies is unprofessional and rude. If I had been a "qualified technician" I probably would have received helpful replies such as "check that you were given the proper relay- I've been given the wrong part many times". I believe that the attitude that only a "qualified" individual should take on a task is what is ruining this great country of ours. I would have appreciated some helpful suggestions as replies, and I would have understood if in those replies the caveat that any error on my part as an "unqualified" person could cause further damage.

  6. #6
    Join Date
    Apr 2004
    In that case buy one of every part and keep changing them until you get it right.

    No professional would try to sell us on the idea that you are pulling 6 amps when the motor is off and we have no way of making a serious reply. A professional would also read the mfd of the capacitor to verify its integrity. Then a resistance reading of the motor may be required along with a running amp draw.

    What kind of help do you want, especially when you are dealing with one of the simplist circuts in a system. The guy at the parts counter is not a professional technician so lets not suggest he is.

    BTW, you agreed when you signed up for this site that there are no DIY questions yet you want to argue that as well after the fact.

  7. #7
    Join Date
    Sep 2001
    Vancouver Canada
    "I was sold the wrong relay by the "professional" at the A/C distributor"

    So you went in and just handed the guy (who should not have been selling to joe homeowner anyway) the part and said I need one of these. Did you tell him it was a 24v coil? Did you not check the packaging when he gave it to you? Call someone to fix your unit, by the way I do believe this forum is NO, I REPEAT NO DIY. Go ahead and keep changing parts till you get the right one or wire something wrong and wreck something else.
    "Go big or Go Home"

  8. #8


    I haven't been given the wrong part many times, that comes from telling the counterman what i want. why didn't you say that you were getting 125 out of the "relay". Lucky that you did not discover that one leg of 220/240 circuit will shock almost as bad as both. and six amps on a motor that's not running is a lot.

  9. #9
    Join Date
    Jan 2004
    You post an amp reading and say the motor isn't running.
    You don't know how to take a proper voltage reading.
    But, you expect be given a technical answer to a vague question.

    Yep, your very capable.
    Contractor locator map


    How many times must one fix something before it is fixed?

  10. #10
    Join Date
    Jun 2003
    Hell Hole Swamp
    Originally posted by ddaddyderek
    [B]I am chastised by the people who left me replies to my query for acting resourcefully and taking on a task that I know I am capable of performing.
    Then why are you here asking us how to do it? This site is not a DIY help site, it plainly states this in the rules you agreed to when you registered

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