"Bypassed" Fuel Relay (Renix)

I REALLY hope someone can help me with this. I've never posted on a forum but I have gotten so frustrated I don't know what else to do. I have a '89 Cherokee I bought recently. When I got it the guy who owned it informed me of the "kill switch" mounted in the dash that his mechanic had installed. "No big deal" I figured. Got home and traced it back to the fuel pump relay. All it was was an on/off switch grounded to the body and then running to the ground leg of the relay's coil. I removed it to see what would happen, turned the thing over and it started fine but the minute I released the key from "start" to "run" the fuel pump cuts off and the engine dies. If I hold the key in the "start" postition the Jeep will keep running. I know the relay is fine and the ballast resistor is ohming out fine. I guess I could leave the switch in place and just turm the fuel pump on and off with the switch but I don't like my stuff to be "rigged" and if I forget to cut it off the battery will die. Any help would be GREATLY appreciated.

Check the wiring and connectors to your ballast resistor. I had to jump my relay until I figured out that I had a bad connection at the resistor.

Tried that. I even cut the ends off and spliced new ones on. I just went downstairs and found that if I unplug all the fusable links off the starter relay I'm getting continuity to + and - on the link labeled "Latch Relay" I shouldn't be getting it to - cause those fusable links are plugged right into the + side of the battery. I'm also getting continuity to both + and - on one of the wires going to the ballast resistor and nothing on the other... this is all with both the battery terminals unplugged and both the resistor wires unplugged.

Are you sure that the kill switch would drain the battery? If this is a Renix, then I think the relay ground is supposed to be connected all the time, and the relay is switched on the positive side. If I'm correct in that assumption, then restoring the ground (by either reinstalling the kill switch or shorting it to ground) would not drain the battery. It's easy enough to test. Reinstall the switch, turn it on, and check for current drain.

^^ that's a good point....

The last time I put in a kill switch, it was because I was having relay issues in a S-10. Put a toggle on the power side of the fuel pump, and just made sure to turn it off every time I walked away. Of course, those GM fuel pumps whine so damn loud it was hard to forget.....

Specific to the fuel relay but largely applicable to most. 86 pin is power in to the (relay) coil, comes form the ignition switch. Actually the same *yellow* power wire to the ignition module. A note, many (most) of the yellow wires in the XJ harness are switched power from the ignition switch.
The 85 pin is the (relay) coil ground, grounds through the ECU (ground switched).
30 pin is constant power through a fusible link (note these are usually red colored wires in an XJ harness).
87 pin is power out of the relay (or switched current) (note these wires are usually a color with a stripe and are functions).
During start the fuel pump gets it's current directly from the starter relay, the fuel pump relay and the ballast resistor are bypassed.
If you plan on keeping the XJ for awhile, get Alldata. They do a pretty good job of breaking down the electrical systems into bite sized pieces. Well worth the bucks, in saved time and aggravation. A whole lot easier to use than the system wiring schematics of the FSM and other publications. They also do a decent job of describing, sensor and components tests.

Yea, according to the diagrams the hot side of the coil is supplied when the key is in the run or start position and the ground is signaled through the ECM. My thing is, if it's sent by the ECM then there is something telling it not to come on. I don't want to be stranded somewhere because of it. I don't like trusting other people's "rigging" if I don't know what it's for.

The OEM solution is usually the best solution. When I first got my 88 I spent the first three days removing the alarm and rewiring everything back to the original.
Solder and shrink tubing is usually the best solution.

8Mud, that diagram you posted, out of all the ones I have, it doesn't look like I have that one. Is there any way you could send me a larger one in case it could help. I tried saving it but it's too distorted once I open it. Don't have it any larger by any chance do ya? (By the way, I still haven't got any further so help is still needed. I'm even willing to supply BEER to anyone that lives close by that wants to swing by and take a look.)

Guess that's all I'm gettin huh?