I have an 96 Aerostar.The otherday the wife told me the "Door Ajar" light won't go off and that all the doors are closed tight. This was right after a good wet snow so i figured something was frozen. I went out, checked all the doors, slamed them good and shut, checked the light and it was off.
Today the wife tells me her dash lights are out and the radio lights are out. In addition to that when she turned the heat on off (the main switch)the rear blower turned on by itself. So I went out and started the van turned on the lights and for sure no dash lights. I played with the dimmer switch and still no lights. For some reason my attention went to the heater switch, it was on off. I turned it on (floor) and the dash lights came on, the door ajar light came on and the radio light came on. I then turned on the rear heat and had full control. I played around and found that if i leave the heater set on floor (deforst or both it didn't matter as long as it was on)and the rear heat off the dash lights stay on, not bright but there on. The door ajar light also stays on.
So just ten minutes ago the wife left to take the girls to a friends house, (now it gets better)she dropped them off and said when they opened the slinding door the dash lights went off and the rear heater came on full blast.
Dose anyone have any ideas? It seems to me that there is something that ties the heater and dash lights togther on the same ground.
Oh yeah before I forget. When the dash lights are on I have no dimming control. One more thing.
When I turn the key to start (one click) the dash lights come on and stay on (even when running) as long as the switchs are set as I mentioned.