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 Friday at 08:13 PM3 days 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...