Keyless question from a newbie
 

I have a 1994 Explorer XLT. My dad bought it new, it's been in my family since day one.

I got the truck in about 2005. It was my daughter's at that point and I never drove it much. But now she's passed it on to me and this truck has an ANNOYING quirk that I'm going to have to fix.

This truck has a dealer added keyless system. I have factory Ford key fobs. And when I turn the ignition on it locks all the doors. It's very much a nuisance. I have a friend at work with the exact same truck wight he exact same system and his doesn't do this.

Leads me to believe I have a bad keyless module or there's a programming issue. I programmed out this feature in my 2004 Explorer. But I can't get this one to go away. Was this thing possibly installed wrong at the dealer? Does anyone have a wiring diagram for it?