1969 Z50K1 - sticky rear brake light switch in cable..

85CTrider

85CTrider

Member
does anyone have a solution to a sticky switch in my rear brake cable? its a new aftermarket cable from chp... front one works fine.. rear one will go on when i rotate handle bars to the right.. i had it run through the handle barrs and middle of forks along the tank and stick under the metal below battery box.. does the cable need to be pinned down to work better? should i take it out from under battery box? is there a way to run this so the switch will work more smoothly?? does the rear brake cable run down the left side of bike ( gear side ) or right side ( kick start side ) ??
 
Last edited:
6

69ST

Well-Known Member
If it were sticking, it'd stay on when the brake lever is released, wouldn't it? Making a blind guess (all that's possible without pix) you've got the cable mis-routed and it's really getting stretched. I'm surprised that the brake isn't being at partially applied, which is activating the switch. Can't advise as to exact OEM cable routing on this bike. That said, it shouldn't be so :censored: tight that steering input has an effect.
 
85CTrider

85CTrider

Member
yo racer.. just so you know im talking about those brake cables with the switch in the middle of the cable.. im not sure how it works.. the next thing i will try is removing the cable routing from under the battery box - where its pretty tight.. looks good and i have seem many people run it that way.. i will just run behind muffler.. see if it makes a difference... does the cable go through the forks or on outside of forks??
 
6

69ST

Well-Known Member
I'd start by un-threading the cable from the bike's frame. Then, attached only at the hand lever & rear cable perch, cycle the rear brake a few times and move the steering through its complete range of motion. If the brake light operates as it should, then it's just a matter of routing the cable to allow normal slack. OTOH, if the brake light activates when the front wheel is turned to the limit, as you've said, then it's an electrical problem, not the cable. Usually best to eliminate potential trouble spots before spending hours trying to chase down something that doesn't exist in the first place.

If this rear brake cable uses the same switch as a CT70 front, it works by compression. When the brake is applied, the two cable sections compress the switch until its electrical contacts have continuity.

Can't advise you on exact cable routing. It's been too long since I've done a complete resto on a Z50 hard tail. I'm a CT70 guy.
 
85CTrider

85CTrider

Member
yo racer.. after another hour of inspection its 100% the brake light switch in the middle of the cable.. i would say its sticky or something.. i tried running the cable in three different spots then finally just ran it beside the bike and all times when i rotate handle bars to the right the light goes on.. i give the switch in middle of cable a small tap and the lights go out.. or i wiggle the handle bars.. the front one works perfect,. this one may be a bad switch?? or am i missing something? does it need to be strapped down? ran a specific route?the switch is triggered by cable compressing i get that.. but teeny tiny amount from bars turning should not do it... i turn out the brake nut on end of cable to make i super loose.. same problem.. i tried tightening it... same problem... any other ideas???
very strange when i make it super loose and it still does it....
 
6

69ST

Well-Known Member
If turning the handlebars triggers the brake light, with the cable under no tension, then I'd suspect a short in the wiring. Disconnect the cable from the bike, at both ends, leaving the switch connected, to the wire harness, and do the steering test. If you get brake light activation, it ain't the cable switch. In that case, I'd disconnect the switch leads (from the rear cable to the wire harness) do the steering test again...if the brake light activates like this (with the switch removed from the circuit) then for sure it's a short in the wiring.

Might seem like needless extra work, it isn't. Mo`better to check twice (three or four times, if necessary) and repair once. A little extra thoroughness now could pay you back with a lot less time & aggravation later.
 
85CTrider

85CTrider

Member
my big question is what do i do if i disconnect it at both ends and turn the handle bars to the right and it does not come on.. then its the cable.. then what do it do???
 
6

69ST

Well-Known Member
In that case, attach the cable to the rear brake, connect the leads to the wire harness, then hold the outer cable in one hand and pull the inner with the other. You might need to use the lever (removed from the bike) to apply enough force. That'll give you fine control over switch pressure. Cross one bridge at a time.
 
85CTrider

85CTrider

Member
its weird.. when cable is disconnected at both ends i can pull the silver end of cable sheething out of each end of the switch,.., one a at a time obviusly.. so i can see the wire going in one and coming out the other,. the pressure from the end of the cable compacting triggers switch.,.. i can see it work fine on the front one.. the back one does not have to much movement and thats why the slightest bit of pressure ( handle bars turning ) causes switch to go on... i assume i have the right switch..
 
85CTrider

85CTrider

Member
I wonder if this cable needs to be pinned down under the tank to work properly.. it seems if its pinned down under the tank and not below the ignition coil it does not go on when bars go to the right... im gonna call chp to see what they say....
should all wires and cables be strapped down under the tank before the tank goes on?
 
Top