Diagnosis and repair of the furnace fan Part 3

[@RayRay-nb7tn]

Some fans trip breakers faster than that, but depends on how far the breakers is too. Sometimes you can't get a reading on meter before it pops. Good video on the the motor. Thank you.

[@grayfurnaceman7640]

Welcome GFM

[@MrKentaroMotoPI]

Great wisdom, Grayfurnaceman!

[@geojor]

thanks for sharing your knowledge ...

[@JoeLinux2000]

Digital amp meter isn't very good for over amping test. Presumably there is a 15 amp breaker that's tripping If it's a 20 amp breaker, your meter is really slow. One furnace I know about has a 10 amp screw in fuse. Of course we could guess it was a bad motor because the furnace was from the dumpster. On the other hand there are a lot of people who discard perfectly good appliances. Furnaces are probably a bit different due to the work related to installing them. Then there are $1,000.00 LG clothes dryers that aren't any good right out of the box due to their poorly designed leaky lint filters.

[@publicmail2]

Figure by oh Feb-March we'll have this fixed.

[@throttlebottle5906]

LOL, he's making sure people pay attention and that it sinks in fully. along with trying to provide the sounds and noises that can occur. yes vision and hearing are two of the first and best trouble shooting devices one should use. noisy areas with many things running does make it harder by far.

[@hopefulfuture1929]

My fan works on On but not Auto, when I turn on breaker the elements come on independent of the thermostat. If I don’t turn on fan, the limit switch turns off the elements. This is an electric Nordyne furnace/AC. I have replaced the sequencer, the limit switch, the control panel and wiring harness. I have a thermostat ordered. Hoping that will fix it! Any tips will be much appreciated

[@throttlebottle5906]

it probably has a bad "time delay relay", BUT it could have broken elements touching each the case and it's nearly impossible to "remote diagnose" without directly testing and knowing and seeing the units wiring, so don't just jump and start changing parts... **why not you ask?** it could instead have a control board with bad relay not running the lower (heating) blower speed vs. high for AC, a bad winding in blower motor or burnt/corroded connector, possibly even weak capacitor, not string enough to start at lower speeds.... ( manual/fan on brings on the higher AC speed), a bad thermostat depending on the system I hope that was enough reasons to not randomly change parts and learn more ;)