Dome light won't turn off

2004 v6 extra cab manual. Dome light won't turn off when the switch is set to door. Tested door switches and they do change state when pressed. Any help would be appreciated.

 

Possible the door switch is shorted allowing the battery voltage to go to ground .

It could also be shorted any place from the Body ECU or Integration relay what ever term you prefer to the door switch

That switch closes when the door is open allowing the circuit to complete by going to ground .

 

The brightness switch might be all the way up but i dont know if its on when key is off

 

Its on all the time with key on or off

 

Where is the body ecu located? I'm familiar with using a multimeter I just don't know where to start.

 

it is behind the fuse block on the left side inside the cab on my 2000 yours should be in the same area

 

Other than the obvious burnt out resistors/cold solder joints is there anything else I should check

 

Your looking for a short between the wires coming off both switches .

burnt resistors and cold solder joint for the most cause open circuits not short circuits

Did you check if the switches are shorted do the easy first .

If there was a short in the wires quite possible it would arc and open the fuse

 

Fuse is not blown. So do I remove fuse and see if I'm still getting voltage to switch?

 

You are 100% sure the switch at the light is not in the on position keeping the light on at all times??

When the switch at the light is in the on position again it grounds via the switch anything broken in the switch allowing it to short to ground could keep your light on at all times.

The switch at the light has 3 positions off Door and On

With the door open the switch is closed allowing the circuit to go to ground via the switch completing the circuit


Your not checking voltage!

Remove the fuse

Does your meter have a audible alarm to check continuity check between the switch and a good ground on both sides . If the meter sounds the tone you found your problem

If you don`t have the audible alarm set to Ohms you will get a 0 reading telling you you found your problem.

Digital or Analog Meter ??

Happy Hunting

 

Key is out and dimmer is set about half way and the dome light switch is on the "Door" position. I have a digital multimeter but im not sure it has the audible feature. I set it to the ohms setting to test for continuity. I see there are 2 wires going up ti the dome light i am assuming 1 wire is always hot and the other is a ground when the doors are open completing the circuit. So if my doors are closed and I disconnect the plug to the dome light and contact the wire that doesn't have a constant 12v and the other lead to ground it should not have continuity until the doors are open. Am I correct at testing it this way?

 

Yes I did test the switches by sticking a test lead into the connector and connecting the other lead to ground and it does change state from open to close when I push the switch so I believe the actual door switches are working fine.

 

I tried I really did

Sorry I can`t help you