Hello and welcome to Just answer,
Below are the instructions for replacing the stop lamp switch, the hardest part of this job is removing the clip, sometimes it can be a bear getting it off, a couple of small screwdrivers help.
Let me know if you have more Questions
Stop Lamp Switch Replacement
No, you do not have to remove the dash this is all done with the seat slid all the way back and then laying on your back on the floorboard, make sure you have a light so you can see what you are doing.
Just to make sure it is the stop light switch, I do have a brake light on the top of the cab just no brake light on the tailend. The bulbs are okay and I have checked everywhere I can think to check so I figure it is the switch. Is there anyway to determine? Thanks for your help.
Nope not the switch,
let me dig into some schematics and come up with a few things for you to check.
Do you have a test light or voltmeter if we need it?
Have you checked the Veh Stop fuse 10A in the under hood fuse block?
I want to find out if it has power with the brakes depressed,
use your test light and connect the clip to the battery negative, place the "ice pic" end on the + battery post to test your test light, if it is working probe the hole in the top of the fuse and have someone press the brake pedal, check both holes in the fuse, both should light, let me know the results
Can you test the CHMSL fuse in the same manner as the VEH STOP fuse and let me know what you get, make sure the brakes are applied while checking.
The CHMSL fuse is located in the underhood fuse block it is right next to the VEH STOP fuse it is #16
Just to clarify,
You have verified that the test light is working?
You were depressing the brake pedal while checking?
The problem is that the chmsl fuse is the protection for the Center High Mount Stop Lamp, power comes through the brake lamp switch on the pedal up to the 2 fuses (chmsl+Veh stop) then the chmsl circuit goes to the cab lamp and the veh stop fuse leads to the rear lamps.
I just don't see how from the results of our tests how the center cab lamp is still working because of no light at the chmsl fuse. no light at either fuse leads to a faulty stop lamp switch on the brake pedal.
One more test check the STOP LPS fuse in the under hood fuse block you don't need to press the brakes on this one.
I am including the schematic that I am looking at so you can see if it helps.
I have to take a break. Can I check this out then get back to you?