Help, I need an answer. I have a 97 f150 4.6L with what I THINK is a faulty electrical ground and I don't know how to find it. All of the fuses and relays under the dash and hood have been checked and are good. If the a/c or headlights are turned on, headlights work, but the a/c fan does not, turn signals and flashers do not work, but park lights and brake lights do, radio LED lights do not work, but radio does, instrument panel lights do not work. This is an intermittent problem and cures up and everything works properly when driven off road, but it always comes back.

Any ideas where to look for the ground problem?