Key Switch Wiring Help 1980 xs1100

[Freedo]

Hello everyone!
I believe my keyswitch was wired wrong and is causing my brake light to malfunction.
From my keyswitch i have 2 wires. 1 is black and 1 is black and white. From that it is tough to explain so bear with me. 2 blue wires are tied into a red/yellow wire and a brown wire and then those go to the black/white wire of the keyswitch. Then one red wire goes to to the black wire of the keyswitch. I cant seem to wrap my head around the wiring diagrams ive seen because i dont think they are specific for the 1980 xs1100 that i have and seem to be for the 79 model. Any help would be appreciated!

[fredintoon]

Hello everyone!
I believe my keyswitch was wired wrong and is causing my brake light to malfunction. - - -

Hi Brad and welcome,
from what you describe the dreaded PO has been messing with the wiring.
What the keyswitch should have is
Red wire that brings power from the main fuse, should be hot all the time.
Red/yellow wire that feeds power to the hazard lights flasher, should be hot all the time.
Tan wire that feeds power to everything else except the rear running light, should only be hot when the switch is keyed to ON.
Blue wire that feeds power to the rear running light, should only be hot when the switch is keyed to ON or to PARK.
Watch that last key position; it's the last small click after LOCK, easy to do by mistake and it will keep the rear light lit all night so the battery will be flat in the morning.
BTW, '79 and earlier do not have a hazard light relay so yes, the diagram will be different.

[Yard Dogg]

Even if the 79' doesn't have the hazard circuit, the color coding will be the same. Yamaha kept their color coding the same for similar circuits for years and years.

[DGXSER]

The 78-79 is different, in that it only has three wires. Red, Tan, and Blue. The Red/Yellow is the fourth wire only on 80-81 switches.

[fredintoon]

Even if the 79' doesn't have the hazard circuit, the color coding will be the same. Yamaha kept their color coding the same for similar circuits for years and years.

Hi Dogg,
except the circuits are not sufficiently similar.
'80 & '81 Standards and Specials all have the keyswitch wired the same.
'79 Special has a Red hot wire, a Tan all except tail light wire and a Blue/Yellow wire to the light checker unit that only that model has.
'78 & '79 Standards have a Red hot wire, a Tan all except tail light wire and a Blue tail light wire.
Researching all these minor differences does make one understand the climate of hatred this list has for Yamaha's wiring.

[Yard Dogg]

LOL, I love Yamaha wiring.

[Freedo]

alright i think i have it figured out. Is this key switch problem any way related to why my brake light is on when the bike is running? I cant seem to get the brake to light up when i pull the handle or step on the back brake but the running light part of it is always on when you turn the key on.

[Petersg_99]

when I turn the ignition switch on if the bike is in neutral, I get the tail light, neutral and oil indicator lights on, brake light will come on with the tail light with ignition on when you put the front or rear brake on. I have to press the brake pretty hard to get the brake light to light too...

The head light doesn't come on until you start the engine

[fredintoon]

alright i think i have it figured out. Is this key switch problem any way related to why my brake light is on when the bike is running? I cant seem to get the brake to light up when i pull the handle or step on the back brake but the running light part of it is always on when you turn the key on.

Hi Brad,
OK, what's supposed to happen when the key is turned to ON is that the blue wire gets powered to feed the rear running light and the tan wire gets powered to feed everything else, including the brake light operating switches.
When either (or both) brake light switches are closed current flows to the brake light filament in the tail light and she lights up.
The headlight is supposed to turn on automatically but not until the engine starts so if the brake light only works when the engine starts it means that the dreaded PO has powered the brake light switches from the headlight wiring.

[DGXSER]

Yes, the tail light will come on any time the key is in the ON or the PARK position. The brake light is just a brighter filament in the same bulb that should come on when either brake light switches are made.

Headlight not coming on until the bike is running is correct. There is a relay in the circuit that gets pulled in by the alternator putting out current. So until the alternator is providing power, no headlight. The relay does stay pulled in until you turn the key off, even if the engine dies.

As to the brake light needing the pedal pushed hard, there is an adjustment to the brake light to change how much pedal movement is required to light it on the rear brake system. The switch itself is mounted into a threaded sleeve, turn the sleeve, it has flat sides like a bolt, to adjust the height of the switch.

[Freedo]

Thanks everyone for your help. I got the key switch wired properly and fixed the brake light. Unhooking the connections and cleaning the contact points is such a helpful thing to do. Once i did that i was back in business.