Im having an issue with a 99 Deville. Originally the wipers worked when they chose, I checked voltage and everything seemed good at the wiper motor and pulse board but I tried another one anyway, had the same result. I ended up wiring the pulse board hot to fix the issue which worked. Prior to that the fuel info on the dash was messed up, still is but now everything is messed up. the stereo will turn off along with the dash lights, at that time the headlights will turn on and the blower motor will turn on high. Has anyone had this issue or heard of such a thing? At first I was assuming the multifunction switch was going but with all these things at once I'm wondering if the ecm isn't failing. The only things I did was check relays and fuses and poke some wires under the dash to check for voltage prior to the lights-dash-blower issue arising. Any help would be greatly appreciated, I'm pulling my hair out on this one! Thanks!