A good friend of mine picked up a '97 F-250 2x4 E4OD with 500K miles on it. Ran pretty darn well, really. He convinced a friend of his to loan him an Edge Evolution tuner(94-03 7.3 PSD model). Connect it up, program to race mode... tons of power! He then shuts the truck off, switches the programmer to extreme mode. Programs fine, but it won't start anymore. Tries to program it back to stock... won't program. Can't figure it out, has it towed home. Now, this is where I came in. What I saw is: 1. with key on, EBPV(or something else near the bottom of the turbo) is constantly clicking. Just click-click-click-click. 2. Unplug PCM relay, the IDM relay now constantly clicks with key on. 3. Unplug IDM relay and PCM relay - No noise, "check engine" light "pulsing" at a high speed. 4. Plug PCM relay in, IDM relay not connected - EBPV clicks slower and more inconsistent - like 1 click/second average. With PCM relay in, no IDM relay, and another truck connected with heavy jumper cables(for higher voltage), I was able to connect the edge evolution again, and after 3 tries, it finally connected enough to program back to stock. When the edge connected and got the PCM into "program mode", the EBPV stopped clicking and everything went smoothly after that. (Note: after programming back to stock, no change. Still clicks fast with both relays in). Now, to me, this strikes me as being a PCM power issue of some sort. Either it's not getting enough power, or something the PCM is trying to output is shorting it out, dropping the voltage below it's "reset" voltage, and repeat. I've tried: 1. Checking all fuses with a multimeter. 2. Found primary power wires to PCM(pins 71 and 97 - both red wires), stripped them back a little, and connected multimeter to them(12.2V or so). 3. Connected both PCM power wires to the battery using my multimeter's 10A current setting(in parallel with existing circuit). One wire drew .25A, the other nothing. So, the PCM is definitely drawing some power, but again, no change. 4. One ground wire from the PCM grounds out on the fender just above the PCM. Checked that with multimeter - 0V to battery negative - so we have a good connection there I think. Now... what should I check next?