I have an issue with my truck, I didn't notice when it started, but my dome light stays on and my third brake light stays on as if I'm in reverse. Does anyone know what the issue could be? I noticed when I tap around the area of the dome light, it'll turn on and off.

 

try this?.... https://www.f150online.com/forums/el...ying-read.html

 

Thanks, I'll try it tomorrow.

 

Didn't work. I noticed if I tap on my dome light, it flickers. Third brake light will turn off after a few hours. Seems like it delays after opening the door.

 

When you say third brake light you mean the cargo lamp ?
- White bulb not the red lens ones.

If this is the cargo lamp, that is part of the interior lamp circuit, could be a few things.

1. If you lock the doors, do they go off ?
- I cannot recall for 100%, but I thought the 99-03 MY had the interior lamp shut off when locked ( theater lighting, dims down ??? )

2. If you turn off the interior lamps with the dimmer switch ( rotate all the way down, past the click ) do they go off ?

3. Are you getting a door ajar indicator in addition to the interior lamps staying on too long ?

4. Have you had a lot of rain as of late ?

5. If you swap the interior lamp relay from the CJB ( aka Central Junction Box, Cab fuse panel ) with another, excluding the battery saver relay, do they go off ?

6. On another try ( the process you need to follow to get the lamps stuck on ) if you swap the battery saver relay with another, excluding the interior lamp relay, do they go off ?

the line of questions is trying to pin point if it is a door switch, maybe a soaked GEM ( if you had rain as of late ) or if the interior lamp or battery saver relay are hanging up.

If it has been dry, I am going to take a stab that it is the one of the 2 relays hanging up and the contacts take time to release, but that is a big SWAG.

 

cargo lamps are tied to dome light, not reverse.....

 

Sorry it took so long to reply, I'm constantly busy.

1. This is what's on:

It shuts off, I just don't know when. Once I open the truck door, it comes on and stays on.

2. The dome light? I'll have to check. I know when I hit bumps or tap on it, the middle light that comes on when the door is open will either stay on or flicker.

3. No

4. Yes, ever since I moved to Florida. I'm thinking it got wet and damaged the wiring harness.

5. I don't know what that is.

6. How do I do that?

 

No problem, this is on your schedule not mine.

1. That is the cargo lamps, they go on with the interior lamps.
- How is this installed ? Is it spliced in or was it a factory connector ?

2. The same interior lamps should be on when the cargo lamp is on.
- Any other modifications to the truck ( i.e. not factory ) ?

4. The rain would more likely be an issue with the GEM than wiring ( unless the aftermarket CHMSL / cargo lamp is having an issue ).
- Pull the CHMSL and check it, and while you are at it, pull the driver's side kick panel and check the carpet for signs of water damage.

5. The relay for interior lamps. It is labeled in the owners manual under the fuse section. Find the correct fuse panel, and pull that relay. Find another one in the panel of the same size ( other than the battery saver relay ) and install it in that place. Think the trailer tow adapter relays are the same size.

If this does not change, put that relay back in the interior lamp position and try it in the battery saver relay position and retest.