1999 Mercedes Benz ML430 Electrical

While driving all warning lighs come on, the fan stops, radio goes off, no window control and if the head lights are on they burn out. Then after a few seconds up to a minute at times, the fan comes back, the radio and everything else starts working again, but warning sound starts beeping, and several warning lights stay lit - bas/esp(?), Parking brake light, abs, ets(?). I will stop the car, turn it off and restart it, this will reset everything but it do it all over again. One shop I brouhgt thought it might be in the headlights, replaced the whole headlight unit, but still doing the same thing. Anything else to check that may cause this to happen.