1978 Z. Started the car, all of a sudden my left blinker went on. Couldn't control it from the stalk. Staid on when the car is shut off. Disconnected the stalk from the wiring harness. The blinker stayed on. I finally stopped it by pulling the blinker relay. Thoughts? My first thought is to replace the relay.

Thanks

It's probably the mechanism in the combination switch.

Not likely to be the flasher. There is no separate turn signal relay.

Pretty easy to remove. Something I learned - the ring around the ignition switch will pop out about 1/8" to allow you to remove the plastic shield around the column without breaking the corners off. Appears to be designed for that purpose.

Edited July 4Jul 4 by Zed Head

On second thought it might be the Hazard switch. Lots of mysteriousness in there. It has power when the key is off.

@SteveJ seems to feel comfortable with it.

"even when car is off"

Has anybody worked on the wiring to "fix" a problem? Those "fixes" frequently involve finding some wire with voltage and tapping into that.

The turn signals are powered through the ignition relay. If the key is not in ON, the ignition relay won't complete the circuit for the turn signals,

As @Zed Head suggested, the next thing to look at would be the hazard lights. Normally if you pull the hazard switch that would kill the power to the turn signals. If the blinker is still going with the hazard switch disconnected, that would indicate some creative wiring has been done to the car.

You can also pull the turn signal fuse to see if that kills the problem. If not, pull the hazard light fuse. The turn signal fuse is in blue, and the hazard light fuse is in red below.

If neither fuse fixes the problem, that still points to creative wiring.

More questions:

1. How long have you owned the car?

2. Have you experienced any other electrical glitches?

3. Look under the dash on both sides and around the kick panels. Do any wires look like they have been spliced, cut, or otherwise altered? If so, look for wire colors (with stripes).

4. Do you see any electrical tape that looks newer than the wiring harness?

This is all great stuff. Thanks. I'll dig into it this weekend. The Hazard light circuit is a high contender since it is the only one to bypass the ignition power circuit. The second thing that points to this is that I took the turn/combination switch/stalk out, unplugged it, and it was still going.

If only the left side is blinking with the hazard switch, that means you have another problem as both sides should be blinking with that switch.

Are you sure? The diagram shows a left side and a right side, from the Hazard switch. It's a 78, I didn't look at any other diagrams.

The Hazard switch is basically a gate between power and the flasher, and the lights. Since the flasher comes in to play the short to power has to include the flasher circuit. Basically it's just completing the circuit, like a short across contacts inside the switch. Interesting problem.

For what it's worth, I erased about three different paragraphs about this problem. Writing about it does help the brain work...

First of all, thank you for all the amazing and detailed information. Apologies for the slow response. I had a bunch of trips. So here is where I am at. Half idiot and half mystery.

Idiot part-I put my phone on the Hazard light and defroster switches and turned them on. Hazards on wasn't my first instinct, because only one side was blinking. So I started diagnosing it as a blinker problem. After I disconnected the Hazard Unit to prevent it from draining the battery, the defroster still managed to kill the battery becasue I hadn't figured out it was me hitting the switches yet. So next step, solve dead battery problem.

Mystery part- Both blinkers don't work (lights and dash indicators) now when actuated by the turn signal stalk. But the left one is the only one that works when the hazards are on (still does that . Fuse is good, bulbs are good.

I checked the stalk before like I said and it seemed good. I can take it out again and do a pin out with an ohm meter next.

Open to suggestions.

Thanks, Adam

On 7/4/2025 at 12:44 PM, AdamSozay said:

left blinker went on. Couldn't control it from the stalk. Staid on when the car is shut off.

2 hours ago, AdamSozay said:

Both blinkers don't work (lights and dash indicators) now when actuated by the turn signal stalk. But the left one is the only one that works when the hazards are on

Not really clear what the "current" problem is. Blinker won't go off would be a short to power problem. Blinker doesn't work at all would be an open circuit problem. Also not clear what you mean by "Both blinkers don't work (lights and dash indicators) ".

Just trying to understand. The Hazard switch has a left and right circuit and its own power supply and flasher to flash the lights. I think that it could have been the source of the first problem.

Does the left blinker still stay on when the key is off?

Edited Sunday at 12:45 AM2 days by Zed Head

2 hours ago, AdamSozay said:

Mystery part- Both blinkers don't work (lights and dash indicators) now when actuated by the turn signal stalk.

Was the hazard switch plugged in when you tested? Flasher units?

2 hours ago, AdamSozay said:

But the left one is the only one that works when the hazards are on (still does that . Fuse is good, bulbs are good.

You probably need to test the hazard switch. Do you know how to use a multimeter?

Current symptoms:

I do not have a right or left blinker when I use the turn signal. The outside turn signals and the dash indicator do not go on for either direction.

When I put on the Hazard switch, only the left side of the car flashes.

Yes, I do have a voltage meter.

Yes, I did plug the Hazard switch back in before diagnosing.

The left blinker no longer stays on when key is off because I turned Hazard switch off.