No intrument panel or tail lights

[iceref63]

I have aquired a 2001 Mercury Mountaineer and am having a problem with the instrument panel not illuminating or the tail lights working. All guages in the panel work correctly as well as the LT\RT and hazard. Headlight works as well as the dome lights. Have verified that all associated fuses on the side of the dash are good. New headlight switch and dimmer switch. Nothing has worked.

Any ideas?

 

[Pete Deering]

I have aquired a 2001 Mercury Mountaineer and am having a problem with the instrument panel not illuminating or the tail lights working. All guages in the panel work correctly as well as the LT\RT and hazard. Headlight works as well as the dome lights. Have verified that all associated fuses on the side of the dash are good. New headlight switch and dimmer switch. Nothing has worked.

Any ideas?

Grounds!
Ground G100 is on the driver side front fender. Front 1/3 on inside
It could also be the Dimmer module. Is the dimmer turn on?.

Tail light ground is G204.
Location driver door, front driver door body frame.

 

[iceref63]

Grounds!
Ground G100 is on the driver side front fender. Front 1/3 on inside
It could also be the Dimmer module. Is the dimmer turn on?.

Tail light ground is G204.
Location driver door, front driver door body frame. Y

Grounds!
Ground G100 is on the driver side front fender. Front 1/3 on inside
It could also be the Dimmer module. Is the dimmer turn on?.

Tail light ground is G204.
Location driver door, front driver door body frame.

I pulled the ground g100 (next to the battery) off and the left headlight went dim but I got dim instrument lights and dim running lights. Cleaned the grounds and reattached. Headlight came on bright but no instrument lights or running lights. Thoughts?

 

[C420sailor]

@Pete Deering is a walking, breathing Explorer electrical schematic. Impressive

 

[iceref63]

All ground have been sanded and reattached. No change.

 

[Pete Deering]

All ground have been sanded and reattached. No change.

Get out your test light. Start at the fuse and see if you have power at each key points follow the diagram.