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Would appreciate any help that can be given, I've been pulling my hair out on this. I have never been good with electrical stuff, and I recently purchased a '89 Comanche with the fuel tank out of it. I hooked up the fuel tank and tried to start the truck, but the fuel pump will not prime or pump when cranking. I've cleaned all grounds, swapped my relays around, bypassed the ballast resistor by setting a paperclip between the connectors, and still have nothing. The pump works when setting the battery up directly to the pump. I set a paperclip between the 30 & 87 on the fuel pump relay, and still nothing. I checked the ground behind the tail lamp, and even cleaned it up, but still have nothing. I tested the rear lights and they work so I don't think the harness back there is part of the problem. I attempted to test voltage at the connector right before it plugs into the pump, and got 12v during the prime. I'm not sure I tested it right, so any guidance is helpful. I am getting 12v at the starter relay fuel pump ballast terminal connection. I looked at the fusible link on the starter relay fuel pump ballast terminal & it appeared to be fine, I was also getting 12.4v at the link. I'm sure I might be leaving some things out, so please ask any questions and I'm happy to answer. I'm really at a loss of what to do at this point. Any advice or guidance?

I recently came into a 1989 Comanche 4.0L 5 speed manual 4x4 (Pioneer trim). It's rusty, lifted at least 6 inches on 31s, and doesn't run. I could get it to crank over with a battery jump starter, but of course with the dead battery, that cranks slow; however, it wasn't getting fuel. I replaced the fuel pump and tried cranking it over, but again, really slow, and low enough voltage I felt like the starter was using all the power (therefore fuel pump couldn't pump). So I decided to grab my 2000 Cherokee and use jumper cables, but after hooking it up, the Comanche still showed low voltage on the dash, and cranked over even slower than before. I used my multimeter and checked to make sure the cables were actually transferring power from the XJ to the MJ (under the hood of the XJ is extremely muddy), and everything checked out. I still cleaned the connections anyways, but nothing helped. It was basically just clicking like it had a dead battery. So next I took the battery out of my XJ and put it into the MJ and it just clicked like the battery was dead. Multimeter showed 12.7V at the battery, but the MJ dash showed 9V. I tried cleaning connections again, but still just a click like dead battery. When I put the battery back in the XJ, it fired right up like normal, no slow cranking, so I know it wasn't the battery. So now I'm at a loss. A couple things maybe worth noting: 1) When cranking slowly with the battery jump starter, the battery cables would get really hot, like it had to draw a lot of current to slowly crank. 2) A lot of the dash is taken apart as the previous owner said he planned on chopping the whole front off and replacing everything from the doors forward with a 99 XJ (which I will not be doing). The cluster is still plugged in and seems to be working correctly. Any direction would be appreciated. My first thought is that maybe the starter motor is bad, so it's taking a lot of power but cranking slowly. But before I start throwing money at a project I'm just gonna beat up off road (it's way too rusty to restore and only cost me $250), I'd like to see if anyone here has had the same issue.

please help - No dash power Hello, I'm doing a 88' to 98' conversion (Hayduke's Operation Comanche RePower) and lost dash power. Before hooking up the 98' doors I could start the engine and the connected guages, odometer, radio, and heater controls all worked fine. I've been trying to get the dome/interior lights to work- repalced door switches, bulbs, testing wiring, and connected doors, and now the headlight switch controled dash lights work, but the needle guages, odometer, radio and heater controls don't work??? I also never got the dome lights to work via the door switches and when the ingition is on one brake light is on brightly, the ground for that harness is not yet connected, I've checked and improved the grounds, checked & cleaned all fuses, relays, etc. checked that all the plugs are connected well. & disconnected the dome light & door switches not sure if I missed something... The engine will start and run well and alternator produces 14+ volts at battery. Earlier the odometer worked but now after much testing it stopped working, A cluster test confirms everything but the needle guages check out. I exposed the ingnition switch but don't know how to test the 98' style switch? What else do I need to try? I'm very close to finishing the conversion then this happens...Very frustrated at this point as the dash was all in, and now it's all torn down again..and the fuse box...and the steering column.... :fs1: I've looked on the Cherokee sites and no solution yet... Any help greatly appreaciated !!!! My focus is getting the dash working again as the dome light can wait!