sharagim1

I have Lexus RX350 with only 12k mile on it , the light is on for AWD system Malfunction 2WD Mode Engaged, because 4 years just 2weeks passed warranty’s been expired , show to the Mecanic and after check everything he found the wire been Chewed by rat, he will charge my $750 for fix this one , you think can I do it myself or show to other ?

dibl

He is probably proposing to replace the entire wiring harness that was damaged. Which means a lot of the $750 is for the harness, not labor. So you can't save the cost of the harness by doing that remove/replace work yourself.

The non-recommended, non-professional, and value-reducing approach would be to isolate the individual wire(s) that were cut and use solder and electrical tape to close the circuit. That would make the car work correctly, at least for awhile, and be very cheap, but no one would consider it a proper repair and it certainly would not preserve the value of your car, if a future buyer detected what was done to it. Also the loss of the original insulation would leave that wire vulnerable to water intrusion and short circuiting. So maybe you could do a temporary fix while you save your money for the proper repair.