1978 cyclone

[andyc1995]

At first I thought i had a bad switch, but now i've realized its in the wiring. The brake light switch has two brown wires and a tan wire at the plug end, one of the brown wires were missing and another wire spliced in to the second brown wire. not sure how wiring was suppose to be. please help.

[harleysportster]

Here is the wiring diagram

[andyc1995]

I dont have a tach or a headlight switch just the dimmer, but even taking them out of the equation the brown wire that is hooked up to the tach has to be hooked up to yellow on the junction block for any of the lights to work, exept the brake light. then if i hook it up to the tan wire the brake light is the only light that works

[harleysportster]

Andy,
Here is the wiring for the 78 cyclone/liquifire

The 78 cyclone/liquifire does not have a headlight switch, the headlight and dash lights are always on when the engine is running. There is a yellow jumper wire bewteen the brown and yellow wire where the switch would normally plug into behind the dash. The power from the alternator travels thru the brown wires to the light switch connector for both the headlight connector and the brake light switch.
Look behind the dash for a pair of wires grouped together, brown and tan. They are the wires from the brake light switch. The tan wire picks up the power from the brake light switch and travels to the terminal block then to the rear brake light.
Hope the helps,

Attachments:

• 78wiring.pdf (237.34 KB)

[andyc1995]

thank you for the info turn out to be bad switch, i diagnose cars all day and this had me baffled.