Have 98 Envoy with open circuit problem that powers rear wiper..
Hope someone else has had this issue, as wiring harness is mostly inaccessible, except for last 5 feet in Lift Gate.
Does anyone know the wiring harness routing from lift gate to front?
Does it travel down right rear pillar next to tail lights, then along chassis, or does harness stay inside the body to firewall?
Fuses are good in both circuits.
Dash switch is powered from left dash fuse panel. Dash switch only supplies signal to Logic Box on wiper motor.
Engine compartment fuse & circuit actually powers wiper motor via the 'Hot At All Times', ORANGE wire.
Somewhere the Orange wire is open.
Logical place to look is where harness transitions from right top of body to Lift Gate.
Wires bend there opening and closing gate.
Popped the neoprene boot between body and lift gate that protects harness. Tough to get god look at wires without destroying boot. From what I could see nothing looks like a problem.
Wiring diagram attached
All ideas welcome

 

I don't know the exact answer to your question but what I do know is that a large wire bundle passes to the rear under the drivers side floor carpet and this has been the source of most of the wiring failure to the rear, I suspect that most if not all wiring heading back is found here. Leaking windshield, door pin bushings, worn carpet, foot pressure.


George

 

Thanks GeorgeLG,
Was exactly the advice i was looking for! Thank You
Forgot about that wiring bundle.
I did repair the power seat wire under the carpet on my 96 Blazer LT.

 

Thanks for the info, you made my day.I appreciate you for helping me out as well.

 

I noticed a problem with my rear wiper right off the bat the first time I used it. It was completely useless as I have the swing gate for the spare and the wiper only allowed me to see the spare more clearly.

 

Sucess, rear wiper working.
Open circuit was in the neoprene wiring boot between right side upper body and door. Factory wiring is cheapo! Its 20 gage with thin insulation.
No slack in wiring bundle to slide boot or wiring to make repair. Wiring is brittle and didnt want to force it.
Figured best way was to add 6 inches of new quality soft wire.

Wiper motor behind power latch

Detail view of right side boot. Broken always hot Orange wire.


Rear wiper Logic box mounted on wiper motor.
Note the 'always hot' Orange wire on 4 pin logic box plug

 

Nice work. Thanks for the detail which will help others. Were you able to figure out the routing from the fuse panel to the door boot?

George

 

Part of the routing is from under hood fuse distribution box, through firewall, wire bundle traces down under carpet between brake and gas pedals, traveling back to drivers seat.
Sorry I didn't trace it further...
PS
The wiring on our vehicles is getting old, the wire gage small, barely adequate to carry the load and the quality is questionable even when new.
The wiring bundle above is inside a fairly sturdy plastic channel to protect it from drivers feet.