Power Locks and Brake Pedal???

libbybapa · 07-21-2009, 09:51 PM

Really strange issue with my '94 Sidekick. Every time I let up on the brake pedal the power locks all go clunk. All the locks remain in the position they were last placed but they are all activated in the manner in which they were last activated. If they were last locked then they all stay locked and if they were last unlocked they all stay unlocked. You can even see all the buttons wiggle when it happens. As I said, it happens EVERY time I let UP on the brake pedal. Anyone have any ideas on what to look for??

Andrew

shackwrrr · 07-21-2009, 10:00 PM

happened to me but it did it whenever I used anything related to the back hatch. It was the ground on the back hatch. It is most likely a ground problem where its easier to ground through the motors in the power locks than to go to right ground. I suggest that you remove your drivers tail light and you will see a ground in there with 1 or 2 wires going to it. Take it off and clean it up. Then check and clean any other grounds you find

libbybapa · 07-21-2009, 10:32 PM

Yup, great idea. I actually went out and pulled the driver's side taillight, pulled the connector and replaced it and the problem is gone.

libbybapa · 07-27-2009, 02:45 PM

Well, this issue isn't yet resolved and I must say has been very perplexing... I keep thinking I've resolved it and then it does it again. A couple of additional factoids I'd point out. If the tailgate power lock actuator is unlocked, then it does not do the issue. Whenever it IS doing the activation with the brake pedal, the center top brake light does not light up. If the lock actuator is unplugged, the top brake light works fine. The tailgate power lock actuator and top brake light share the same ground which happens to be a screw into the body of the tailgate. Removing that screw and un-grounding the wires causes the lock activation to happen EVERY time the pedal is depressed (it NEVER works correctly) and so my conclusion is that it is indeed a ground fault for the third brake light that is feeding back through the power door locks.

Is the door really just grounded to the body and consequently the battery through the hinge pins???? Is it logical to assume that a routing like that might be the cause of the sketchy ground? I guess I will run a wire through the door bundle in order to actually ground from the door to the chassis and see if the problem is cured. Any other suggestions?

Andrew

libbybapa · 07-27-2009, 11:24 PM

Well, I added a ground wire to the tailgate bundle and screwed it into the door frame on one end and the metal car body inside the taillight area and the problem is 100% eliminated. I did much driving around today and it functioned perfectly.

Tracker Tommy · 07-28-2009, 12:07 AM

Good job! Process of elimination.