Right blinker not working when brake is applied

[capt2130]

I'm hoping someone was had this issue before. When the right blinker is on it functions like it should. When I step on the brake the blinker lights up solid, off the pedal and it starts blinking again. Figured it was a ground so I ran an independent ground, same result. I switched out the light housing & bulb, still no change. I was told it could be the blinker switch in the steering column. Was going to try that next but figured I'd ask the pros. This is on the 72.
Any guidance is appreciated.

Thanks
Tim

 

[Broncobowsher]

I presume you are talking about the rear brake light and turn signal. What I want to know is what happens to the front turn signal? Does it just come on and stay on as well? Without the turn signal on does the front light up when you press the brakes?

I don't remember the '72, does it have the hazard switch on the dash or the column? If on the dash try unplugging it.

Is this something that just started happening? Or did you buy the truck with this problem?

Any extra wiring under the dash? I see St. Louis as a location. Missouri side? Someone may have put a jumper wire between the brake light and the right turn to cheat there way through the Missouri safety inspection.

 

[EricLar80]

If nothing has been changed and it just stopped working, I think it's possible that you have the brake and turn signal grounded to the same spot, and there is corrosion preventing good flow.

 

[capt2130]

I presume you are talking about the rear brake light and turn signal. What I want to know is what happens to the front turn signal? Does it just come on and stay on as well? Without the turn signal on does the front light up when you press the brakes?

I don't remember the '72, does it have the hazard switch on the dash or the column? If on the dash try unplugging it.

Is this something that just started happening? Or did you buy the truck with this problem?

Any extra wiring under the dash? I see St. Louis as a location. Missouri side? Someone may have put a jumper wire between the brake light and the right turn to cheat there way through the Missouri safety inspection.

The front and back are doing the same thing. Only the right side. Both flash until the brake is applied. Then both stop flashing and go solid.

The 72 doesn’t have a hazard switch. Believe it was introduce in 73. But I could be wrong.

This bronco had the problem when I got it. Looks like someone had been tinkering with it and not in a good way.

Everything else works fine. So I was hoping it would be painless fix. Without having to install a new painless harness lol.


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[capt2130]

If nothing has been changed and it just stopped working, I think it's possible that you have the brake and turn signal grounded to the same spot, and there is corrosion preventing good flow.

Thanks I’ll check that.


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[Tuloyuser]

The blinker could also be bad.


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[Broncobowsher]

Blinker won't cause that.
It's either a butchered wiring harness or a bad turn signal switch.
Bad grounds will do some weird backfeeding, you get turn indicators lighting up with headlights and stuff like that. But what you are describing is a short between the brake signal (off the brake pedal) and the right side turn signals (after the switch). And those also come together inside the switch, thus a bad switch is possible.

Look the wires at the brake switch over for something extra spliced in. If you see a splice, try unhooking it and see what happens. No splices, turn signal switches go bad often enough I would be putting one in.

And the '72 had a hazard switch originally. It was there. Might be missing as part of that bad butchery of wiring.

 

[capt2130]

Blinker won't cause that.
It's either a butchered wiring harness or a bad turn signal switch.
Bad grounds will do some weird backfeeding, you get turn indicators lighting up with headlights and stuff like that. But what you are describing is a short between the brake signal (off the brake pedal) and the right side turn signals (after the switch). And those also come together inside the switch, thus a bad switch is possible.

Look the wires at the brake switch over for something extra spliced in. If you see a splice, try unhooking it and see what happens. No splices, turn signal switches go bad often enough I would be putting one in.

And the '72 had a hazard switch originally. It was there. Might be missing as part of that bad butchery of wiring.

Yes it has has a hazard on the dash. Meant to say on column. That said when the hazards are on the rear does not flash at all. Front stay flashing even when brake is applied. Thinking it was to be wiring. Will try to get back to it later today.

 

[Broncobowsher]

The hazards stay flashing even with the brake applied? That's not right. The hazard switch sends out 3 signals. One to the left front turn signal, one to the right front turn signal, and one to the brake circuit. It takes all 3 circuits and combines them and puts a flashing input into them. Applying the brakes should put a solid (non-flashing) power to the rear brake lights and backfeeding through the hazard switch lock both the front turn signals on solid as well. Over ridding the pulsing hazard into a solid light as long as the brake is applied.

You have to remember a little on what the turn signal switch does. It not only sends a pulsing signal to front and rear signal bulbs, but it removes the rear signal bulb from the brake circuit. That way the brake light won't keep it on all the time.

 

[capt2130]

The hazards stay flashing even with the brake applied? That's not right. The hazard switch sends out 3 signals. One to the left front turn signal, one to the right front turn signal, and one to the brake circuit. It takes all 3 circuits and combines them and puts a flashing input into them. Applying the brakes should put a solid (non-flashing) power to the rear brake lights and backfeeding through the hazard switch lock both the front turn signals on solid as well. Over ridding the pulsing hazard into a solid light as long as the brake is applied.

You have to remember a little on what the turn signal switch does. It not only sends a pulsing signal to front and rear signal bulbs, but it removes the rear signal bulb from the brake circuit. That way the brake light won't keep it on all the time.

I checked the connection at the column and saw a pin wasn’t seated correctly. I reseated and now have hazards working correctly.

Going back to the blinker on the right side. It still stops flashing when brake is applied.

I’m just going to switch out the blinker switch and see what happens.


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[capt2130]

Blinker switch didn't fix it.

Anyone know of a good electrical troubleshooter in the StL area?