datzenmike, thanks for your rapid reply. My name is Gregory, I am Cristina's mechanic and friend. For the record, I am a professional. I run my own shop and have been turning wrenches for a long time. She posted the original question and then realized the issue is over her head so I am taking over. Hope that's okay. Let me clarify the sequence of operations on the truck so far. When she first got it, the area needing the most attention was the front end (steering and suspension). While taking care of that I noticed it had some funky wiring issues. Nothing crazy, especially considering it's age. There were a few things unplugged underneath but most notably there was a jumper wire run to the fuel pump directly from a switched source. Probably to bypass the relay. I tested the relay and it seemed to be working fine so I reconnected it. At this point, Cristina had already replaced the fuel pump and filter on her own. I figured those components must have been the problem all along. After reconnecting the relay, the truck ran fine for my test drive and I gave it back to her. Then her intermittent stalling issues began. The truck would run fine and then just die out. about 30 minutes later, it would start and run fine again for an unspecified period of time. According to her, there didn't seem to be any rhyme or reason to it. Not when it was particularly hot or cold or long or short distances or stop and go vs. highway. It is also worth noting that the carburator situation was a mess. Over the years, vaccum lines and switches, etc. had been disconnected and rerouted. A common picture in vehicles of this era and I am sure you are familiar with this. She had already planned on upgrading to the Weber carb so I said let's start there and see if that fixes the problem. When I did the carb swap, I also dropped the fuel tank to check for debris and blew out all of the lines to eliminate that as a potential. Everything was clean. The carb swap was smoothe and when I went to fire it up, there was no signal to the fuel pump. The relay was definitely not coming on. I figured I caught it in action, so to speak, so I put in a new relay. At the time I didn't know about the easy fix. Just when you think you know all the tricks. Truck fired right up and was driving really well until a few days ago when it randomally died again (same issue as before). At this point I am convinced it has something to do with the relay situation, especially considering the chronology of everything. Ran with jumper wire, removed jumper and died intermittently with stock relay, replaced relay, ran for a month and started to die again. I asked her to leave the key on the next time it dies, roll to a safe stop and get out and check if the pump is still on but she hasn't had that opportunity yet. Today I checked continuity at the relay plug to ground and the oil pressure switch, all good. I also checked voltage from the ignition switch, starter switch, and the alternator, all good. I pigtailed the ground to a ring terminal right on the screw that holds the relay to the body under the dash. Just to eliminate that one. That didn't work because it died again on her way home. I ordered a new oil pressure switch that Cristina will put in today, although I am not confident that is the issue. I don't think low oil pressure is the issue either because the truck runs and sounds really strong and smoothe and the oil looks good. At this point, I think it is something in the wiring harness and if the oil pressure switch doesn't fix the problem, I will just run all new wires and a new relay that just supplies switched 12v to the pump directly. Unless you have a better idea. Can low voltage from the alternator cause this kind of problem? Any help or suggestions would be great. Sorry for the long winded story, just wanted you to have all the info. Thanks for your time.