Fixing Nissan blower motor "resistor", amp, controller, whatever

Working on a 2004 Quest, here I take apart the blower motor amplifier that has many names. It receives a PWM signal from the main HVAC controller, and has a large switching transistor for control. Find out what goes wrong.
I've also done this on an Infiniti QX4, so it's probably a fairly common failure.

[@sulistomobambang]

I should try perhaps, but my blower its doesn't work at all fuses and relay works fine and blower test directly working fine too

[@mustanggta5444]

@FixItCheap I have a 2011 chrysler town and country I having a really weird issue nobody can figure it out I be driving it then all of a sudden it gets stuck in one gear nothing I do helps it get out of that gear then I have to pull over shut it off let it sit for a few seconds then turn it back on and it drives beautifully no hard shifting shifts into every gear then after driving a couple miles it does it again gets stuck into a gear then have to shut it off again and works fine when I go from park to drive I do hear a real bad clunk from the side pan sometimes it doesn't happen all the time this van is very Bazaar just got it 3 weeks after it was driving fire for couple weeks then this last week it started doing it it has the same codes p0734 p0735 p0733 thank you

[@CheapskateGarage]

Is it always the same gear it gets stuck in? Or does it vary? Driving around with a bidirectional scan tool could give some insight, unfortunately they're quite expensive. Before taking the compounder apart, I would track down all the speed sensors and verify their operation. You can ohm them out, and then ohm them out again through the PCM connector to verify harness integrity. Also check for corrosion in all the connectors.

[@CHEAPROLLIN]

Buy a dipstick and check fluid. It uses ATF plus 4. You are not stuck in gear you are in limp mode. Dirty fluid or wrong or low. I will help you

[@CheapskateGarage]

@@CHEAPROLLIN Good point, always a good idea to have a dipstick for the trans. I marked the backside of my engine oil dipstick according to some dimensions I found online. I can now use that dipstick for either the engine or the trans, and I always have it with me.
Line pressures should be reported on a good scanner too, and can help indicate whether oil delivery is an issue. Low pressures can definitely cause slippage resulting in these speed mismatch codes.