Hey y’all,
I have a 1989 Jeep Cherokee 4wd Laredo. Been chasing a electrical demon, I had a no start no crank issue. Fixed it with a new ignition switch pigtails. The switch I replaced for piece of mind. The red wire and the brown wire melted in the old pigtails.

I had a burned out fusible link at my Starter relay. I replaced and was up and running.

put everything back together, started the Jeep and it ran great. Let it idle for awhile and watched the engine bay. It was great. Went to turn off Jeep and key turned but stayed on. Radio turned off when I turned the key off. Pulled the fuel pump relay while key was in off position and Jeep died as expected.

with the relay pulled out, Jeep starts up and turns off by key. I am stumped.

I used the Jeep to go around the blockZ. Again the Jeep died as I parked it back at the house. Lost all power. I try to start again. I smell burning. Turn the key on the off position. Open the engine bay and see two smoke sources. One next to my relays and one next to my drivers side firewall.

a yellow wire is melting. Pictures are attached. Anyone have an idea on where to start. I don’t want to replace wiring just to have another wire melt again. Based on these symptoms, anyone have an idea?

engine schematics would be appreciated but I ain’t that smart to read those things.

also, I have followed cruisers tips and have completed the ground refreshing and updated all cables from Jeep cables. 2 gauge.

 

Pictures

 

Your fusible link burned for a reason... it is as if you have a chafed wire, or multiple, somewhere. Are you sure your ignition switch pigtail is wired correctly?

The ignition key has multiple switches inside for more than one circuit, but powered by the same link if I recall. One circuit does the following: ignition RUN/START-related on the load-side of the ignition switch, typically a yellow wire. Another circuit powers ignition RUN-related things, typically an orange wire, on the load-side of the switch. Then there is the START-related circuit, typically a green wire, and lastly an ignition-RUN/START/ACC circuit with a brown wire. Another part of the ignition switch, closes a ground for other things like warning lamps/guages. Your yellow wire melting indicates, to me, that you have a short somewhere related to RUN/START wiring (things capable of operating while the ignition switch is the run or start position, but won't work in accessory position).

Removing the fuel pump relay is supposed to remove power (when it is energized and closed) to the fuel injectors, A/C clutch relay, O2 heater relay and fuel pump- fed by the orange ignition wire. However, the fuel pump relay is powered by the yellow ignition wire.

 

Yes I believe the ignition switch was wired correctly. I cut one wire at a time and took notes and pictures before just to double verify.

any good tips or tools that I can use to find the maybe chafed or damaged wire causing all this?

Also, I don’t get how the Jeep stayed on without the fuel pump relay. I know I didn’t hear the fuel pump whining.