Found the 10amp thermal fuse blown on the circuit board inside the green blower motor resistor. I found a box of them for $8 on Amazon. Soldered in a new one and it works great again. 5 hours labor tracking down the problem for an $0.80 part. Could do it again in less than 1 hour now.
View attachment 836295
Many thanks
I went down this rabbit hole on my 2014 Dec Model S 85, checked fuses in GEN2 FJB (front junction box), all 4 were good (to check you use a voltmeter on OHM setting OL is good for fuse, bad will show resistance must replace).
Bought a replacement blower fan from Tesla (resistance was a bit better than the one I took out) - didn't need it my brushes are fine inspected them.
Well have a spare now.
After seeing this post I removed the fan motor controller, I used the OHM meter to test this thermal fuse, it was not OL it was showing resistance a bigger number.
Normally I would buy the replacement part, but Tesla did not have it in stock, no local parts cars to grab from, and did not want to wait a number of days in the hot hot
sun.
Found the part at local electronics store, wife picked up the part and got some solder paste first time using.
I tested the new thermal fuse and it showed OL (open loop) which meant it was good.
[Remove plastic cover to access electronics under]
I cut one arm of old thermofuse bent the circuit board back, unscrewed the mossfet cover, dropped the thing, green plastic cracked (super glue later)
Note: the black part of the fuse is facing the larger thing on top, I'm not too sure if orientation makes a difference but I replaced it the same way
I had to desolder the pins, on both sides, I have this suction thing where once you get the lead melted you uses suction thing to pull up the solder.
Bent the new one in place, scraped off the thermal white residue in put it on the new thermal fuse, then while putting the two ends of wires in the circuit board, I bent the board back so I could get the screw back in place on the mosfet.
I try to desolder the three wires for the mosfet thing but I wasn't successful.
Bending works, as long as nothing breaks.
Then I used solder paste for the very first time, was able to melt the lead solder onto the pins, and beefed up the mosfet 3 pins that I was trying to desolder.
Upon plugging this in, my blower fan started to spin immediately. I just saved thousands of dollars from taking this to Tesla for a $15 part, replacement thermal fuse was $2.97 from the electronics store.
Put the glove box and interior back together, now my 10 year old over $100,000 car is whole again.
It has the face lifted bumper.
AC Air Conditioner Heat Heater Not Blowing Fixed