95' K1500 Chewed wiring, No Speedo, No 4X4 & 4l60 in "Limp Mode"

[LOUDRNU]

Hello everyone, Ive been scouring the forums and figured I needed to post for assistance. I inherited my grandfathers 95 K1500 Z71 with the 5.7 at around 140,000 miles. It always ran and drove fine until my grandmother parked it in her barn after his passing. Upon driving it home i quickly noticed it had major issues, it felt like it was limited to 2nd gear, if I remember correctly I was able to manually get it in 1st but it shifted very harsh. No speedometer, the PRNDL lights do work but it does have a ABS and Brake light. The 4x4 buttons do absolutely nothing. Also SES light for heated 02 sensors (p0141?)

Getting under the truck i quickly realized rodents had chewed through 2 of the 02 sensor wiring harnesses. On the vehicle side of the harness of course, the one being further back almost above the transmission running to the downstream sensor, and the other one near the dipstick tube for the transmission which seems impossible to reach without removing the transmission or cutting an access through the floor pan.

From what ive gathered the heated 02 sensor and the transmission share the same power source, (pink wire) and i'm guessing this could be causing some if not all of my issues. If anyone has had experience repairing or replacing these harnesses or tips on possibly accessing them without removing the transmission it would be greatly appreciated. Thanks in advance!

 

[Erik the Awful]

You're going to need to start with wiring repair. Once that's done you can reassess your issues.

 

[RichLo]

Mouse chewed wiring problems is going to be a headache nomatter what. For the things that you can see like that o2 sensor you can buy a replacement harness section and fish it through and splice in where its more convenient.

I would go through it with a fine tooth comb and find everything that you can where mice have bitten then go to a scrap yard and start pulling those wires out of a treasure truck.