brake lites

[akamcbird]

so i noticed when checking my tail lights in a window reflection, that there not as responsive as they should be. because ide prop the brake pedal with a stick then walk around the truck to check the lights, ive never seen how much pedal pressure it takes to light them up... quite a bit, more than i generally use to decrease speed or even come to a complete stop.

 

this problem is in my '90, the '87 is buried in snow so i couldnt check, but the neighbor kid whos truck is identical to mine has the same issue.

 

 

has anyone had this problem? does anyone have a fix for me? i really cherish the rear half of my truck, and apparently i don't have the funds to replace the tails with anything comparable in quality to what i have....

[beaterjeep]

I'd start by checking the wiring behind the driver's side tail light. Check for any corrosion on the tabs, and any broken (weather checked, loose insulators, etc) wires. It could merely be an issue of a corroded tab not getting enough power through it. Also check the ground back there, IIRC it's connected to the bed somewhere back there. Someone more knowledgeable than I should be able to correct me if I'm wrong.

[dasbulliwagen]

Ive yet to deal with the MJ's brake light switch, but from what Ive seen most are adjustable. If it is adjustable, maybe try to set it so it comes on with the slightest brake pedal movement. The brake lights have nothing to do with the amount of pressure you apply... I know some companies do it like that, like my old air colled VW's, but your truck has a switch at the brake pedal, try to adjust it and see what happens!

[akamcbird]

the switch is adjustable... thats what I'm after...thanks much

[mjeff87]

the older style switches on our MJ's aren't adjustable per se, they are a funky little arrangement that attach via the through-bolt on the top of the pedal rod. It's a spring loaded switch with a small plastic shim inside of it that can become very finicky. You may need to replace the plastic shim to get yours to function better.

 

Newer style (mid-90's XJ's) use a plunger-style contact switch at the top of the pedal assembly, which is vastly easier to adjust.

 

Jeff

[jteckmann]

the older style switches on our MJ's aren't adjustable per se, they are a funky little arrangement that attach via the through-bolt on the top of the pedal rod. It's a spring loaded switch with a small plastic shim inside of it that can become very finicky. You may need to replace the plastic shim to get yours to function better.

 

On the older trucks, the bolt can also work loose and the switch falls out of position. At least, that's what happened on my '86. Was driving in town, and a guy pulled up next to me at a stoplight and (thankfully) told me my brake lights weren't coming on. Pulled into the parking lot to check fuses, and that's when I noticed the switch was angled down towards the floorboard, and wasn't making contact with the pedal. I tightened it up for the drive home, then I put a lock washer and some threadlocker on it so hopefully it doesn't happen again.

[akamcbird]

the older style switches on our MJ's aren't adjustable per se, they are a funky little arrangement that attach via the through-bolt on the top of the pedal rod. It's a spring loaded switch with a small plastic shim inside of it that can become very finicky. You may need to replace the plastic shim to get yours to function better.

 

Newer style (mid-90's XJ's) use a plunger-style contact switch at the top of the pedal assembly, which is vastly easier to adjust.

 

Jeff

good info thanks, ive glanced at it a few times but ive got to pull my dirty floor mats out to get a good look,tomorrow ill be doing a bunch of random work on the truck so itl be in the garage for the weekend ond i wanted all the info i could before my fingers were to greezy to type

[jpnjim]

There is a long delay, because the electricity in our trucks is 20+ years old now, and has slowed down over the years.

 

Longbeds have this problem especially bad , because the electricity has so much farther to go to get to the taillights.

 

:D

 

 

The type of switches used on the Renix's was strange (like others posted), I replaced mine with a Ford style plunger switch, after a little tweaking of the plugs, it actually plugged right into the old harness.

 

I had to weld an L-bracket to the side of the brake arm to give the switch a nice flat surface to work off of, and also had to make a clamp to hold the switch.

 

It would probably be easier to swap in later parts, but all I had was 97-01 pedals, and I didn't want to swap the whole pedal set just to get a better brake switch. :dunno: