Rear Brake and turn signal lights are not working?

2005 FORD EXPEDITION

246,794 MILES • 5.4L • V8 • 4WD • AUTOMATIC

ALSTON RAASCROCK

MEMBER
3 POSTS

The high mount light is working.

I changed all the bulbs (3157) rear stop and signal bulbs.

I checked the fuse 2 and 18 both look good but replaced it

I checked the brake socket with a voltage meter, and it read 7.9 volts.

I turned on the turn signal and went back to the socket, but no current was coming through the wire.

The red light that illuminates when you open the door isn’t lighting, may be the bulbs.

I also pierced the wire on the turn signal to see if any power is coming thru the wire “no beep” on the voltage checker.

Please help

Aug 16, 2023 at 1:02 PM

STRAILER

✓ASE Certified Mechanic
54,837 POSTS

It sounds like the multifunction switch has gone bad. But to be sure let's test for power through it. here is a guide that will help and the brake light and blinker wiring diagrams so you can see which wires to test and how the system works.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

this guide may help as well:

https://www.2carpros.com/articles/brake-lights-not-working

Here is how to replace the multifunction switch in case you need it. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Aug 16, 2023 at 4:41 PM

ALSTON RAASCROCK

MEMBER
3 POSTS

I got the bulbs working again, thanks to you.

Sep 4, 2023 at 7:02 AM

STRAILER

✓ASE Certified Mechanic
54,837 POSTS

Way cool, can you tell me what the problem was?

Sep 5, 2023 at 10:42 AM