I have an 89 GMC Sierra pickup and the courtesy lights stay on. I've replaced both of the door switches and the lights still stay on. I've pulled the fuse for now. What else can I check???

Check fuses under the hood on driver side

do you have the light switch on? also there is a little switch on the door that gets pressed when you close it this part could be broken causing the car to think the door has been left open thus leaving on the courtesy lights

courtesy lights have a 3 position switch 1 is for doors open --on /off 2 is for light off permanent and 3 is for light on in car permanent for reading etc. Other than that check the door switches for a permanent earth fault.

The door switch has been integrated into the latch mechanism on many GM vehicles,but I believe the switch can be replaced seperately.You will have to pull of the door trim panel to get at it,so you can probably do it yourself,depending on your skill level.

the return spring is inside the power booster(what the master cylinder bolts to) but most likely it is the brake light switch the box on the pedal where it coonests to the booster shaft

either you have a short in the fuse box assembly or a short in the main swtich, trying pulling the fuse and checking it. if the fuse is fine then its a short in the 2 areas i listed above....Pull the fuse in the mean time to turn off, or check the door jams and make sure the the actuatore shafts are all still there that turn them on and off with the doors opening and closing... or pull the bulbs....Good luck! hopethis was helpful

in the door jam you have aswicth, myte be cover with
rubber skin remove the rubber and unsrew the little
switch and replace it with anew one start with driver
door its the most used ( remove fuse first)

Have you tried the switch on the dash that turns them on? Are door switches adjusted properly?

Have you check the door ajar switch in each door?