The 1987 Jeep Wrangler YJ was the first generation of the model and featured a unique wiring system. It includes the main harness, relays, switches, plugs, and ground points that work together to power the vehicle's electrical accessories.. I see some diagrams showing a wire from that main starter relay post to the battery. My setup is currently battery to main lug on starter, but nothing to the relay. (which I figure can't be right because that would mean that little solenoid wire would be carrying all the power to the relay).
![[DIAGRAM] 90 Jeep Yj Wiring Diagrams](https://www.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/08/ad/58/large/0900c1528008ad58.gif "[DIAGRAM] 90 Jeep Yj Wiring Diagrams")
I have a 1987 Jeep YJ with the starter solenoid on the firewall. I'm only getting 3v on the signal wire any ideas. What?. Then check the starter & solenoid for internal shorts. (Ive seen some wierd stuff along the way, including a brush assembly that broke and the spring shorted out an entire starting system). Unfortunately, you will have to cut open the wiring harness and replace all burned wiring. Be careful to seperate any fused together wires without breaking.