no interior lights 95 classic

[FB111]

No interior lights by opening a door or using the interior light switch. Getting 12 volts at the dome light but I guess no ground. Was having some strange switch behavior, open passsenger door and rear windscreen heater comes on and real faint door warning chimes. Replaced the fuse box under the steering wheel and all the peculiar behavior disappeared but still no interior lights. Don't know where the ground is specifically for the interior lights and welcome any other suggestions.

 

[ezzzzzzz]

Is it only the interior roof lamps? Do the door puddle lamps work?

 

[FB111]

Puddle lamps aren't working.

 

[ezzzzzzz]

Definitely sounds like a ground issue. The heater is acting as the ground I suspect. The ground (E201) associated with all of this lighting and several other circuits can be found behind the left footwell panel. It is below a bank of relays. You can't miss it. I'd start there.

 

[FB111]

The multiple ground behind the drivers footwell panel seems fine. No corrosion, took it apart and retightened to no avail. However I found a strange phenomenon. I took my voltmeter to an overhead interior light and I get 12.5 volts on both sides of the terminal with the bulb removed.

 

[FB111]

Update: Got all the door lights to work. Someone had cut one of the wires to each of the lights. They stay on for a couple of minutes before turning themselves off. Still no overhead lamps by opening the door or using the switch on the dash. Does this suggest the switch is bad?

 

[FB111]

Swapped interior light switch from my other truck and I now have interior lights operating from the switch but not by opening the doors. Getting closer....