Driver Side Hazard Flashing When Off 1974 Plymouth Valiant Scamp

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DigitalRelay

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I replaced my destroyed turn signal switch with one from Amazon. Although the connector was a pain in the *** to get connected, I eventually got it. I only have one flasher right now, but when plugged into the turn signal circuit, everything works as expected. When plugged into the emergency flasher circuit, all four corners flash when the hazard switch is on, but when the hazard switch is off, I still get driver taillight, front turn signal and side marker flashing, although they seem dim. If flip the turn signal lever down (without the turn signal flasher plugged in), left lights go out, no more flashing. If I remove the front turn signal lamp while the hazard switch is off and left lights are dimly flashing, the flashing stops and side marker and rear lamp stay on. I've searched for shorts, but I'm starting to suspect the turn signal switch. Any ideas?
 
Update. After much messing with wiring harnesses, sockets and checking grounds, I pulled out the recently replaced Chinese turn signal switch and my multimeter showed some low resistance between connections that should be open. I've messed around bending pins and checking connectors and it seems to be working right, but I'm not installing it in the car. I'm sourcing a quality part.
 
I tried hooking the TSS back up, same problem.

I used the old TSS harness to hook up only Emergency Flasher power and LR and/or RR. No turn signal flasher installed, no turn signal flasher power hooked up. Rear lights still flash with hazard switch off.

Taking a closer look and using the multimeter, the Emergency Flasher feed lands on the TSS as a blue wire on the bottom center terminal on the hazard switch. The top left terminal on the hazard switch has a white wire that goes underneath to the right terminal on the turn signal cam. That in turn feeds underneath to a terminal that feeds LR, and a second terminal that feeds RR.

Whether the hazard switch is on or off, that top left terminal with the white wire is hot, which sends power to LR and RR lights. I would expect with the hazard switch off, the top left terminal would not receive power. When hazard switch is on, it would send power to that terminal, which in turn goes to LR and RR lights. But maybe I'm missing something.

This is really an exercise in understanding the switch and wiring better as I still intend to replace this switch regardless.

Is that top left terminal at the hazard switch supposed to always be hot?

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From @67Dart273

HOW DOES the hazard flashers work?

The hazard flasher always gets hot power. That power goes to one terminal of the switch you showed. That leaves three terminals. One other goes to the left turn lamp wire, one other goes to the right turn lamp wire, and this leaves the last switch terminal. THAT terminal goes to the TS switch on the same terminal as the brake light switched power.

How does this work? With the hazard switch OFF, all 4 terminals are open, nothing is made to anything.

With the hazard switch on, ALL FOUR terminals are jumpered together. This causes hazard flasher power to route to both front lamps, and to the brake light switch line. With the TS switch centered, the TS switch then routes that hazard flasher power to the two rear brake lights.
 
Woodys_Cuda said:
From @67Dart273

HOW DOES the hazard flashers work?

The hazard flasher always gets hot power. That power goes to one terminal of the switch you showed. That leaves three terminals. One other goes to the left turn lamp wire, one other goes to the right turn lamp wire, and this leaves the last switch terminal. THAT terminal goes to the TS switch on the same terminal as the brake light switched power.

How does this work? With the hazard switch OFF, all 4 terminals are open, nothing is made to anything.

With the hazard switch on, ALL FOUR terminals are jumpered together. This causes hazard flasher power to route to both front lamps, and to the brake light switch line. With the TS switch centered, the TS switch then routes that hazard flasher power to the two rear brake lights.
Click to expand...
This is great! I’ll re-read and take another look when I get back in the garage.
 
Woodys_Cuda said:
How does this work? With the hazard switch OFF, all 4 terminals are open, nothing is made to anything.
Click to expand...

TSS in neutral.

With hazard switch off, the emergency flasher feed is connected to both the bottom white wire terminal that feeds the rear lights, and the top white wire from the stop light switch feed.

With hazard switch on, the emergency flasher feed connects to the yellow and green terminals for thefront lights, and the bottom white wire terminal that feeds the rear lights, but the top white wire terminal from the stop light switch feed no longer connects to anything, including the bottom white wire terminal that feeds the rear lights.

If I'm understanding this correctly, with the hazard switch off, I should not have continuity between the blue wire terminal (em flasher feed), and the bottom white terminal (feed to rear lights). But I do.
 
That description I wrote only applies specifically to the older cars with the separate, dash mount hazard switch. But the idea is the same. Without sitting down with one and going through it, I could not diagram it. In the old days I fixed mine and a couple other guys where the hazard switch failed and kept the stop lights from working. I just moved a wirein there and re-soldered it, then cut the knob off the hazard switch so it could not be activated, LOL

I would guess in your case., that some contacts are improperly "floating around" in the switch.
 
67Dart273 said:
That description I wrote only applies specifically to the older cars with the separate, dash mount hazard switch. But the idea is the same. Without sitting down with one and going through it, I could not diagram it. In the old days I fixed mine and a couple other guys where the hazard switch failed and kept the stop lights from working. I just moved a wirein there and re-soldered it, then cut the knob off the hazard switch so it could not be activated, LOL

I would guess in your case., that some contacts are improperly "floating around" in the switch.
Click to expand...
Yeah, that's what it seems like to me. I guess I'll order a quality TSS and then I can compare to make sure. Thanks for the input.
 
No response yet on a quality switch, so I bought a second cheap one to compare. It is wired and acts exactly the same way. I'm confused. With the hazard switch off, the emergency flasher feed on blue is connected to the stop light feed and the white lead that goes to the terminals under the cam that feed the rear lights. Since the emergency flasher feed is always hot, with the hazard switch off, it's still feeding emergency flasher power to the rear lights. Surely I don't have two faulty TSSs with the same problem?

After more searching, I found this diagram that seems compatible with my hazard switch.

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As others said above, when the hazard switch is in the off position, the hazard flasher feed on the hazard switch at D1 is supposed to be open to all other terminals. Mine is closed to the H2 terminal shown in that diagram whether the switch is off or on. Ugh. I guess I'm opening one of these up to take a closer look.
 
Well, it seems at least one of TSSs had a bad hazard switch. I pulled it apart and one of the copper tabs fell out.

I then had to experiment for 45 minute bending and squeezing the two copper tabs so that they made or didn't make contact with the right terminals depending on whether the hazard switch is on or off. What a pain. I ended up squeezing the "hump" part on the larger piece to narrow its point of contact, but I went too far on one and had to go back and flatten it. I've got it working according the multimeter right now. I'll temp connect it in the car and test before I fish it down the column.

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