Okay, it really did. I was pulling off the freeway into town, and in the middle of the offramp, a short sweeping curve, I reached up to adjust the rear view mirror and it fell off (it's an aftermarket mirror, and if I tighten the screw, it deforms and falls off, so I have to leave it a little loose). Just as it fell off, and right in the middle of the curve, the truck died. I coasted down the off-ramp until I got to the stop sign. When I went to restart it, it wouldn't. Hmmmm???? I crawled up into the engine compartment and took a quick look, but nothing was obviously wrong. Then I got back in and turned on the key to notice that the CEL did not illuminate at KOEO. Ok, ECM failure or blown fuse. I didn't relish trying to figure out the fuses while I was in the middle of the road, so I called my son. We pushed it off the road, and he looked at fuses. Sure enough, the IGN fuse was blown. I carry a lot of spare fuses, so we put one in. No luck. Both the ECM1 and ECMb fuses were good. Okay, the ECM is dead. I drive him back to work, drive the 25 miles home to get my 8625 and pigtail wire harness adaptor, then drive back to the truck. I hop in, remove the connectors from the 7747 and install my upgrade ECM. Still no love My fusable link? I drive back to my son's place of work, and as he is about to get off work, I hang around the 20 minutes, we print out wiring diagrams, and grab his snap-on probe. When we got back to the truck, we probed A1 on the ECM 12V on 7747 ECM. It had 12 V with KOEO Okay, the fusable link isn't blown. Then he put 12 volts on the output to the fuel pump and it doesn't turn on. Oh Cr@p. I'm laying under the truck and not hearing the fuel pump prime. Then he says.. How about now? Yep the pump primes. I get in, re-plug in the 8625 ECM and the truck starts. It runs like dog doo, but it starts. Okay??? I unplug the pig-tail and replug in the 7747. The truck starts and runs perfectly, and my son is laughing. The mirror apparently hit the tank selector switch as it fell, and it was stuck between the two tanks and not supplying voltage to the fuel pump . So you see, the mirror falling off caused my truck to quit running. The only thing I really got out of this is that the truck does not run well with a stock 350 bin in the 8625. Live and learn.....