LoveMy98

Hope someone can help, i am getting my brake light and abs light come on when i start my truck, sometimes it is right away sometimes 30 secs later. I have replaced the speed sensor, all brakes and lines are new. The funny thing is i also have problems with the power mirrors and driver side window. There have been occasions when i dont get the idiot lights and my mirrors and window work. Coincidence? Or could this be a problem with the ECM? I have also heard that ford did a factory splice on wiring coming through the firewall that gets corroded from water leakage. So i need to know if the splice thing is true and if so where is it, and i cant find the abs module. I think its in the dash but dont want to dig unless i have to. If you have any suggestions they would be appreciated. 1998 f150 4.6l 4x4 vin w.