No rear hazard lights

[guyryan100]

67 C10 with a replacement auto column (no tilt). Blinkers and all other lights work. When I switch on hazards, I get front lights blinking, no lights in the back. Does anyone know if this is the switch, the relay, or something else?

[RustyPile]

Originally Posted by guyryan100

67 C10 with a replacement auto column (no tilt). Blinkers and all other lights work. When I switch on hazards, I get front lights blinking, no lights in the back. Does anyone know if this is the switch, the relay, or something else?

Unless you are calling the flasher unit a relay, there isn't a relay in the system. If even only one light blinks. then the flasher isn't the problem.. If you have brake lights and turn signals, then probably the turn signal switch is bad..

[Richard]

Ground on bed is the first thing I would check. Circuits can find a ground though other sources when they are not used.

[damnyankee36]

Originally Posted by RustyPile

...If you have brake lights and turn signals, then probably the turn signal switch is bad..

I agree. You might get lucky and try wiggling or activating the T/S switch several time to see what happens. Might be just a temporary bad connection.

[MARKDTN]

Are you sure you have brake lights?

[kwmech]

Originally Posted by MARKDTN

Are you sure you have brake lights?

^^^ This. I'll bet you don't

[guyryan100]

I just went outside to double check because of course I have brake lights, obviously I checked that, but humbly you are correct - I don't have brake lights and of course I didn't check that prior. I do have rear running lights but brakes.

[rockyrivermark]

Best advice I’ve heard on this board is this.
When it comes to electrical issues.
“Check your grounds first. Then second, check
Your grounds again”

[guyryan100]

In this thread, tmjlambert provided this:

Turn signal switch connector wire colors (dash wiring harness side):
white = from brake switch, has voltage if brake pressed
yellow = to left rear light, has constant voltage if brake pressed and if turn signal not in turning left position. has voltage flashing on and off if turn signal switch in turning left position.
green = to right rear light, has constant voltage if brake pressed and if turn signal not in turning right position. has voltage flashing on and off if turn signal switch in turning right position.
light blue = to left front turn signal light
dark blue = to right front turn signal light
purple = from turn flasher, has voltage flashing on and off if turn signal switch in turning right or left position.
brown = from hazard flasher
black = horn, horn button will ground this wire and cause horn relay to turn on

I tested each of these and found that I do have power coming from the pedal switch, but I do not have power going to yellow or green wires when I press the brake pedal. I do have blinking power on those wires with the turn signal, the turn signal lights do work.

So I would conclude this is a turn signal switch issue - power is going into the switch from the pedal but is not coming back out. Does that sound right?