Battery light won't go out?

Just registered to this site. A lot of very good useful info! Thought I throw in my two cents...I've been having a problem with my battery light. New batteries, and alt! They were all on there last leg. Never had a prob with the light. Now won't ever turn off. So...That little plug on the top of the alt. There should be 12V at the orange/blue wire when the key is on. Mine didn't have the voltage, this means alt not running at 100%. I couldn't jump start my cat, let alone a toyota, I tried. My batteries wouldn't stay fully charged. Always had slow starter speed. Sometimes would drain the batteries trying to start. In the warm months(above 50) i delt with it. Cold months(under 50) It was a PITA!:blah: Today was the last straw! Had bats tested, alt too.........All fine! I noticed a main wiring harness connector under the turbo intercooler pipe attached to a bracket just above the vale cover. Removed intercooler, and intake pipes. Loosened the bolt that holds the harness plugs together. I was going to check the wire in question for 12v at the harness plug. Guess what? Didn't have to cause the bottom side of the plug where the loom, and tape ends... Exposing all 1million wires to the engine, heat, oil, grease, fuel, ass, salt, more oil, diesel, ect. I think you get the point. Well, the half million on the bottom side were either missing insulation, or just completely halved. No blown fuses .All because they were rubbing on the valve cover. Nice job Ford/International. NO wonder the truck ran like poo! After a long period of time and many swear words I got it put back together. Behold!!! LIght is out, Voltage stays up when trying to start! F'n Glow plugs work(replaced relay too) Its like I traded in a Bus for a large ferrari! So short story long...If your battery light wont go out. Alternator and batteries are good, no blown fuses(yet)...CHECK the underside of that harness plug! I have a 99. I am willing to bet my ridiculous government salary that 95% of the time this is the cause on the ole 7.3! I researched and researched to no avail. I noticed a trillion threads with no real answers. I hope this one is real and helps out some one with the same problem!