Well, the ignition switch sends that power to the EEC relay coil, so that's pretty much all that's left.
If you HAVE to drive it, do the jumper. Might also check the battery negative cable has a good ground to the radiator support. I'm pretty sure that's the ground for that relay (see if that EEC relay socket #85 has continuity to ground). Should be a ground from the battery to the block, another from the head to the Wiper motor, a couple on the DS fender, another from the chassis to the frame under the cab, and I'm not sure where else.
Hopefully, someone with an 88 wiring diagram will throw you a rope.
Bueller?
If you HAVE to drive it, do the jumper. Might also check the battery negative cable has a good ground to the radiator support. I'm pretty sure that's the ground for that relay (see if that EEC relay socket #85 has continuity to ground). Should be a ground from the battery to the block, another from the head to the Wiper motor, a couple on the DS fender, another from the chassis to the frame under the cab, and I'm not sure where else.
Hopefully, someone with an 88 wiring diagram will throw you a rope.
Bueller?