Horn/brake light/turn indicators not working all the time

Frans

Supercharged
Joined
Mar 5, 2021
Messages
417
Ride
2015 Rocket roadster
No problems with the brake/horn/indicators before starting, it starts without any problems, at 2000rpm the voltage is 14.5v (neutral) but when riding the horn does not work. The brake light and the turn indicators might or might not work while riding. Hard to pinpoint a condition that will cause this, it will just either work or not.

Fuses all look good.

any ideas ?
 
maybe a loose/broken/almost broken common cable maybe in top of something. at higher vibration could be losing contact? maybe a ground?
 
Here's some useful information for you:
Roadster 4.png
Roadster 3.png

Roadster 2.png

Roadster 1.png

Not sure which Roadster VIN you have, so I included both wiring diagrams.
 
After a cursory glance at the wiring diagram, your problem may be the ignition switch... which is known to go out. I see that the indicators also run to the tachometer, any chance the tach's gotten wet?
 
any chance the tach's gotten wet?
Not that i know and when it happened it was dry

Ignition switch was also on my mind. Specially when turning the key on and all was fine and then for testing moved it into P, after getting it out of P the brake/horn/indicators did not work which was an exception to the situation that those always work when turning the key
 
weird thing is that sometimes the indicators do not work but i still operate them and then when slowing down and coming out of the turn they start working.
 
maybe a loose/broken/almost broken common cable maybe in top of something. at higher vibration could be losing contact? maybe a ground?
yes, maybe as ground is indeed the only common cable for them all.
 
yes, maybe as ground is indeed the only common cable for them all.

i dought it would b ground prob.
do not have time to study diagrams
going from memory i think the components that r giving u probs is on one circuit of the ign switch.
that may be why it works some and then not. every time u turn the key it will connect but some times bad connect with low volts.
u can monitor voltage or replace ign an hope or u can install fuse with extra wire to a known good source and see if the prob still exist.
 
if it was ground or ignition switch would then not also the head- and tail-lights show the same issue? Those ligth up the moment the key is turned and they never turn off
 
if it was ground or ignition switch would then not also the head- and tail-lights show the same issue? Those ligth up the moment the key is turned and they never turn off
I think that the headlights r on a different circuit of the ign switch.
often u have one circuit of ign switch bad and the other good.
 
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