1987 YJ, 4.2L with auto trans.
Truck has no back up lights AND starts in any shifter position. remove and replace switch on driver's side of trans(easier if you drop front shaft).
Didn't help. No change.
when I pulled the old switch and compaired it with new, I notices the inner plunger(there are two) was stuck inward but alas changing the switch didn't fix the issues.
What am I missing other than tracing my harness?? Previous owner replaced starter solenoid on firewall......wired incorrectly??