Great video. My old Goodman had blown the fuse on the board and traced it down to shorted coil on contactor at outside unit. I had replaced it just 2 years before because of ants. They don't make replacement parts very good anymore.

notes: at the 12 minute time, when he gets shocked, this is because the thermostat low voltage wires are hot. that 24 volts at around 1.5 - 2.0 amps. Not enough to really hurt you, but you notice. The better way to disconnect all power FIRST. There is a possibility that you can end up causing damage to the thermostat, and the brand new transformer all over again, doing this "work when hot" work. The same applies to disconnecting power. It's better to insert back probes into the wire nuts on a live low voltage thermostat circuit if you want to test with the meter. this insulates the test equipment and prevents the leads from touching and shorting to other things... I am not opposed to the technique in this video...but to the inexperienced DIY, there is a real risk of causing alot of problems if you are not careful about what you are doing... otherwise, an excellent video showing top level troubleshooting techniques.

GREAT low voltage real world diagnosis and repair! ♥

Thank you for the tip, low voltage short is my fear when i 1st start doing hvac

I actually can't believe how many manufacturers don't put LV fuses in their equipment, I've seen the plastic in those transformers can catch fire from an LV short. My brand new Goodman packaged unit that I installed last year did not have an LV fuse from the factory, I certainly added one when I was wiring it all up.

Have u ever tried the new Wago lever wire connectors? Theyre an awesome alternative to wire nuts. The wagos r especially nice when ur wires r short. The inline wago connector actually extendes the wires slightly. No more twisting wires.

i have one contactor doesnt pull in and voltage on connections are 0v disconnect from contactor now i have 24v and then when manually push contactor in burns transformer so i say shorted low side of the contactor

How did you know the transformers was bad

My unit is similar to that of yours, it doesn’t have a 3 Amp fuse so the transformer keeps blowing. How did you wire the resettable amp popper into the circuit? Did you just use red ( power ) and one of the 24V wires off of the transformer to complete the circuit?

Great video. I'm a subscriber to your channel, and I have learned a lot, BUT, you have said in a previous video titled ( how to choose a transformer) that a 3 amps fuse is too much for 40VA , and it will blow the transformer! How come you install a 3 amps ? Just asking out of seek of learning. Thx.

where can i get those pop up fuses?

On a carrier package unit if I replace a missing transformer how would I wire it, the unit has no schematic. Does one low voltage side go to the Red on the Board and the other go to the common on the Board? Or one to the Red on the Board and the other to the Contactor?

What brand and model is the crimping tool

What type of meter are you using?

What is a low voltage short mean. Thanks.