2001 F150 xlt weird goings on
 

Hello Ford experts, lets try this on for size: My son in law has a F150xlt 2wd auto trans 4.2 cruise, it is over 100,000 miles. This truck has had its share of problems, but this is a new one. Claims battery dies and needs a jump to get it going again. He finds out that the dash is staying active and odometer is staying lit when the key is removed. Acts like the key is still in the ON position. The only way to turn off the dash is disconnect the battery. Next day reconnect the battery and ddrive. Get to destination, disconnect the battery. So there you have it, now where does it go, yep my house. Ok it is just like he said, the Inst cluster is still active with the key out, Well I have no schematics and looking on the forums everybody forgets to put the year and model truck the schematic is for, I guess they think they are all alike, well not so. Anyway started troubleshooting this thing and for no reason the heater blower started running (yes heater was in the on position), keys are not in the Ignition, and out of the blue this happens. Ok lets start pulling fuses. get to fuse #15 5amp in dash fuse panel and the Inst cluster gous off and the heater blower stops. Plug fuse #15 back in, Inst cluster comes alive and heater blower starts. Turn heater blower switch to off and blower stops, thats perfect. Turn heater blower back on and off it goes, wow this is messed up. Wiggle stuff in general, beat on dash nothing changes. Ok this sounds like a poor connection or a back circuit due to a bad ground someplace. Lets take a shot in the drk here PCM or the brains.. Remove battery to get at the one PCM connector. remove battery box. Remove PCM connector at firewall and plug back in. Do that two times. After made sure it was properly installed , replaced battery box and battery. truck started right up and dash no longer stays lit when key is removed ???? For 5 days now the truck has been running better than ever they say. What I do not understand is how did fuse #15 in the dash fuse box kill the blower motor?? Fuse #15 has nothing to do with that at all. I think some of the schematics I found are not correct for my truck which once again is a 2001 F150xlt 4.2 ltr.
Any Ideas out there in F1150 land???
Thank you
Darryl...