2010 Lexus RX 350 — fan won’t blow after jump

[Cougar]

Well good find. You now have two possibilities for the trouble. There is either a short in the wiring to the blower or the blower itself has a problem. I think you previously tested the blower by applying power directly to it. If so the blower could be drawing excessive current and still work. I assume the blower motor isn’t getting jammed somehow and can run freely. A jammed motor will draw excessive current. To see if there is a short in the wiring you can use your test light probe by clipping on the positive power point that provides power to the fuse module. Place the probe tip on the contact for that fuse position that the fuse module plugs into. You should see the light turn on. Next, disconnect the blower wiring and then do another probe check. If there is a problem with the wiring the light will go ON again and you will need to track down the short in the wiring. If the light doesn’t turn on then it appears the blower motor is causing the issue. I don’t know the design of the blower assembly but I suspect there is a speed control circuit inside it and that is what is causing the problem.