Bert shows his Carrier Infinity blower diagnostic process using a multimeter.
In a Carrier Infinity system, the blower is in constant communication with the board. However, when the blower motor doesn't communicate back, an error code shows up. In this case, we have an error code 44, which may point to a failed module or board.
Instead of replacing the module and using the process of elimination to diagnose the problem, you can use your meter to see how much voltage the board is actually sending to the module. In this case, Bert reads ~240v going into the blower motor. Then, Bert checks the control voltage and sees if there is between 12 and 13 DC volts of power between the red wire and common at the blower plug; the readings are right on target. The reading between the common and yellow wire should be around 5 DC volts; Bert reads ~1.6 volts, so the board isn't sending the proper communication voltage.
In the end, Bert would have replaced the wrong part if he had immediately replaced the module without testing it with a meter.
Read all the tech tips, take the quizzes, and find our handy calculators at https://www.hvacrschool.com/.
In a Carrier Infinity system, the blower is in constant communication with the board. However, when the blower motor doesn't communicate back, an error code shows up. In this case, we have an error code 44, which may point to a failed module or board.
Instead of replacing the module and using the process of elimination to diagnose the problem, you can use your meter to see how much voltage the board is actually sending to the module. In this case, Bert reads ~240v going into the blower motor. Then, Bert checks the control voltage and sees if there is between 12 and 13 DC volts of power between the red wire and common at the blower plug; the readings are right on target. The reading between the common and yellow wire should be around 5 DC volts; Bert reads ~1.6 volts, so the board isn't sending the proper communication voltage.
In the end, Bert would have replaced the wrong part if he had immediately replaced the module without testing it with a meter.
Read all the tech tips, take the quizzes, and find our handy calculators at https://www.hvacrschool.com/.
Okay, I Just wanted to. uh, talk about checking a communicating blower motor we have. This system is the communicating Affinity carrier system and we have a control board that talks to our blower motor and uh, when the blower motor doesn't talk back, if we get an error code, we're flashing 44 on the board. here.
our control panel inside is reading the error code 44. So we have the likely issue of a failed module since that's more common possible issue of a failed board. and I'm going to help you identify which is which you can play The Guessing Game of grabbing the module and putting it in and then finding out that we still have an issue. Or you can actually find out how much voltage this board is supposed to send to the module and confirm that the board is actually doing its job.
Get the right part the first time. So here we go. First thing you want to confirm is that your blower motor is actually getting high voltage. So you should have 240 coming in to your blower motor.
So let's check that. Okay, I got 240 making it to the motor. All right. So the next thing we want to make sure is that our motor is receiving the proper voltage control voltage.
Now this is a DC voltage that gets sent out and that's you know, a similar Trend with like a train communicating systems or Goodman communicating systems. Whatever it is, you're going to have a DC voltage. It may vary So actually calling Tech Support and finding out what the proper voltage should be for this uh, type of system, it's going to be important. So right here we have our common which is our green and then our power on red and so between green and red we should have about 12 the 13 volts.
DC Let's go ahead and switch our meter DC and check now. I Like to do it at the plug at the blower because that lets me know that the voltage has made it all the way through the harness to the blower. So this is my preferred way of checking this. so you can see we have 12.6 DC this is Right On Target I should have between like 12 and 14.
14 would be a little bit high, but um, that is my power voltage powering the module controls power from the board and then I should have between my common which is green and yellow about five volts. So let's see what we got here. Okay, and I'm not getting that. So right now I have 1.6 and I should have between three and five.
So that lets me know that my board is actually not sending out the proper communication voltage and so I could have replaced this module and then been stuck. Um, realizing that I should have grabbed the board instead. So this is why this test is important. The minus symbol is because I don't have my black lead on common.
Um, but as long as you really you realize going on there. But let me just demonstrate that if your black leads uncommon because it's not alternating currents direct current 1.6 it'll still show you mostly minus but you get them. You get the point there. I Hope Well, there we go. Saved ourselves an extra trip. Now we know. Uh, we need to grab a board here. Let's do that.
What are we waiting for? All right as a finish. I'm just going to show you what the board actually should be reading. The new board is sending out 4.9 uh between yellow and green whereas before we had like 1.6 and then also let's check 12 volts 12.6 So we have the proper Um voltage coming in and the and the actual call to run and there's our call and then if the modules failed um, then it's not going to be sending voltage back on Blue to communicate to the board. There you go.
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Supco makes a ecm motor tester too.
You da man, Bert!
Bro, thanks for clearing up the minus on ur meter. I had seen it on mine and had forgotten what it meant. When I saw urs and u ended up explaining it. very nice.
Thanks! You can use a motor tester as well, plug and play. If the blower turns on its the board if it doesn't its the motor.
This is a secondary check for me after checking voltage.
Just went through this today with a Bryant , I had code 41 though.
Good stuff Bert Service area Kanata??
ive had those motorwinding side fail on lennox, lots
of moisture signs though and stiff turning
Thanks good stuff
Can you do a similar video for infinity gas valve and inducer. Are you in Orleans ?
👍
great video..thanks!
Thank you Bret.
Awesome video
Good info
Good job straight to the point m