No brake light / left hand indicator....

[1978sierra]

Hey guys,

I have a light issue that's driving me nuts in my 78

My driver side rear indicator is not working. the bulb comes on when I turn the lights on but I get no flash when I signal, and no brake light when I brake. I have replaced the bulb and the flasher.

When I put my hazards on, my front drivers side flashes as it should, and both green arrows blink on the dash. When I put my left turn on, the front lights illuminate but don't flash and the green light on the dash stays lit up solid, indicating a burnt out bulb.

I pulled out the rear light assembly to take a couple pictures. it seems like there is more going on on the left than the right. I have included images of both.

Any insight would be amazing.

Cheers,

[Bandit130]

I had a similar issue on the 72 I use to have. Found problem with turn signal switch in column. May be a possibility on yours too. Just passing that along that you may want to check.

[KQQL IT]

Originally Posted by Bandit130

I had a similar issue on the 72 I use to have. Found problem with turn signal switch in column. May be a possibility on yours too. Just passing that along that you may want to check.

Same issue on my '73

[cadillac_al]

In my experience it is always the grounds. You can unplug the taillight harness and probe the terminals with a test light and verify that the voltage is getting back there.

[homemade87]

I just had this issue , But mine is a 82 . No turn or brake light drivers side . Mine turned out to be in the bulk head on the fire wall . Pulled it apart and had power to the bulk head but was not getting to the harness to the rear . Replaced the male connector in the rear harness and works fine now . As said above check to see if power is present at the tail light , if not next step is the bulk head . If power there move to the inside of the cab .

As always check all ground to make sure there clean .

[1978sierra]

Here's an update as I still have not been able to solve this issue.

To explain again:

I have all running lights
I have both reverse lights
I have brake light and signal on the passenger side
I have hazards on everything but rear drivers side

I have no brake light/ signal on drivers side rear, signal illuminates but does not flash on drivers side front.

--

I needed to replace my turn signal switch anyway to solve a horn issue. I replaced it and now I've got the horn I was hoping that this might also solve the problem.... It did not.

I replaced the socket for the turn/brake bulb with another one. no change

I grounded the new socket a different location.... nothing

I removed the ground that was coming out of the rear harness, lost passengers indicator, brake and hazards, so I reconnected it.

connected multimeter to ground and yellow wire on new socket when active, got a reading, connected to brown wire and ground got nothing.

I am beyond stumped. Can anyone help me?

currently I have what looks like factory wiring coming to the rear: Yellow, Brown, Green, Black.

At the back bumper splits to driver passenger side.

Driver side has ground connect, and other wires that run back to trailer harness and license plate lights. There's another ground there.

Any help would be greatly appreciated.

Cheers,

[rwhit57]

Check the wires to that side. a wire can be broken somewhere along the way without appearing damaged. You can ohm it or run a new wire to replace it.

[Pontiac1976]

The rear lights, come from the firewall down the driver side to the back of the bed has like a trailer plug see if your getting power there on all the wires.
The bulbs for the brake turn singal should be #1157 bulb.