No Reverse Lights - 4.0, AX-15, 4x4

[88Wonton]

Hey y’all, couldn’t quite find an answer to my question so I’m starting this new thread. I’m trying to get my 88 Comanche to pass VA inspection and the last thing I need is reverse lights. This trucks been a mess of electrical gremlins but I’ve got everything working except reverse lights. The plug had melted on the exhaust before I bought the truck and the little jumper that goes from the 4-flat to the Transmission switch was gone. So I decided I was just going to hardwire the dang thing and isolate the two that aren’t used. That resulted in working reverse lights but my brake lights are now on constantly. My rear blinkers still work on both sides cause I know the blinkers override the brake lights in Comanche wiring but regardless of whether my headlights are on or not, both upper and lower bulbs in my taillight housings are on constantly. It may be both filaments in the dual filament bulbs, I haven’t visually verified that but I know it’s at least the high intensity filament in the dual filament bulbs. Any insight would be helpful. Really trying to get this thing road-worthy this week. Thanks yall. 
         - 88wonton

[pizzaman09]

I've not looked closely at the reverse wiring in these trucks, but why do you say there are two unused wires?

[88Wonton]

On 3/13/2025 at 7:53 PM, pizzaman09 said:

I've not looked closely at the reverse wiring in these trucks, but why do you say there are two unused wires?

The Reverse Light wiring harness that runs on the passenger side of the engine block ends in a 4 flat style plug. From what I’ve gathered here in this forum and others, that 4 flat plugs to a jumper that goes from 4 wires down to 2 so it can plug into the transmission reverse light switch. Leaving 2 wires just jumpered together and not attached to anything. I could be wrong but that’s been my understanding so far. My truck didn’t have reverse lights or even the jumper when I bought it. 
 

below is attached a pic of the 4 flat connector that you can has obviously been melted on the exhaust. 

[Ωhm]

Connector looks like C111. C111_A and C111_B should go to your Backup lamp SW. C111_C and C111_D when jumped together connects the Upshift lamp to the ECU.