Forum Discussion

BobSchaar's avatar
BobSchaar
Explorer
Jun 20, 2019

Break controller

Took my trailer out for the first time last weekend. I noticed that my trucks's (2001 Silverado) brake pedal is not activating my brake controller. If I use the manual slide on the controller box, the trailer breaks work fine. A local hitch installer told me to check the fuse for the 3rd (high) break light. Apparently the controller is powered from that light? I havent had the opportunity to check this yet. It worked fine when I put the trailer in storage last fall. Anyone else have this problem?
  • pauldub's avatar
    pauldub
    Explorer
    Jun 20, 2019
    The brake controller isn't getting a brake signal from the truck or the controller is failing.
  • PHM4LR's avatar
    PHM4LR
    Explorer
    Jun 20, 2019
    You might also check the brake light switch just above the brake pedal,may be intermittent. I had the same problem once.
  • Campfire_Time's avatar
    Campfire_Time
    Explorer
    Jun 20, 2019
    PHM4LR wrote:
    You might also check the brake light switch just above the brake pedal,may be intermittent. I had the same problem once.


    X2. I had to replace this switch on one of my trucks for exactly the same reason.
  • mapguy's avatar
    mapguy
    Explorer
    Jun 20, 2019
    Before replacing the brake light switch, check the fuse for the Center High Mount Brake Light. It is located in the fuse panel located on the end of the left hand dashboard end. Open drivers door and look at end of dash for access panel.


    EDIT - the CHMSL fuse powers part of the brake controller function on this era GM full size truck
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 20, 2019
    Easy way to check the high brake light Numnber one...
    IN the evening or after dark back into a parking spot in front of a store that is closed and observe the reflection of the rear of the truck as you step on the brakes in your rear view mirror (Hey that was easy only needs one person)

    Method 2
    Have your partner stand behind the Truck and observe as you apply the brakes.

    NO light = Either bad bulb or blown fuse.
  • BobSchaar's avatar
    BobSchaar
    Explorer
    Jun 26, 2019
    I had my daughter check the high mount brake light the other day. It isnt working. I haven't had the chance to check the fuse yet but will likely tonight. I will have to get the owner manual out and figure out which fuse it is. Don't recall if the truck uses the normal size fuse, or the smaller fuses.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 26, 2019
    Well now you know the problem. Time to find the solution.. I've been having fuse issues on this rig too but I think I may know the cause Will investigate more later.. Working on steps just now (not working. new motor is under counter about 7 miles away will Pick Up tomorrow PM and install) Getting the old one out (Steps stuck in retracted) was fun but.. I found I have all the needed tools. (Well I had to make one).
  • mapguy's avatar
    mapguy
    Explorer
    Jun 27, 2019
    Should be fuse 13 in the left hand BEC (end of left hand dash)-10amp

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