96 explorer indicator light

I have a 96 ford explorer that is driving me crazy. The dimmer switch works correctly on the dashboard lights but it messes up the other things. With the headlights turned off all works normal, when I turn the headlights on - this is where the problem begins. Four things happen. With the light turned off all is normal. The overhead temp and direction are at full brightness, the radio is at full brightness, the FWD light comes on like it should, the FWD LOW comes on as it should, the OD OFF light comes on as it should, and the speed control light comes on like it should. BUT --- TURN THE HEADLIGHT SWITCH ON AND NONE OF THE ABOVE LIGHTS COME ON AS THEY SHOULD. Any Ideas????

I am having same exact problem on my 96. Have you fixed problem? Have replaced headlight sw, inst panel light dimmer. Still have problem. Trying to find a detailed wiring diagram. Really don't want to go to Ford if I don't have to.