Brake lights and hazards not working! Help

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dan0340

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Ok I have a 1973 duster. I had all of the electrical dialed in last month and now all of a sudden the brake lights and hazards stopped working. I have power at the break pedal switch both sides and power at the hazards flasher on both sides. The tail lights work, the turn signals work. All other inside lights are working. I can’t hear the hazards flasher clicking either. I switched it with blinker flasher and blinkers still worked fine but not the hazards. All fuses are good of course. Any help would be greatly appreciated!
 
One side of the hazard flasher runs to a fuse and the brake light switch. The other side goes to the turn signal switch(pink wire). Check for power on that wire going to the TS switch. I'm looking at the wiring diagram.
 
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dodgemahal said:
One side of the hazard flasher runs to a fuse and the brake light switch. The other side goes to the turn signal switch(pink wire). Check for power on that wire going to the TS switch. I'm looking at the wiring diagram.
Click to expand...
Right, so I checked for voltage on both sides of those pink wires when the flasher is plugged in. What I’m getting is power on the side with the two wires (running to fuse power and brake switch) and then power on the single wire running to TS only when the hazard switch is in the off position. When I pull the hazard switch there is no power running to that wire. Is that how it should be?
dodgemahal said:
One side of the hazard flasher runs to a fuse and the brake light switch. The other side goes to the turn signal switch(pink wire). Check for power on that wire going to the TS switch. I'm looking at the wiring diagram.
Click to expand...
Right, so I checked for voltage on both sides of those pink wires when the flasher is plugged in. What I’m getting is power on the side with the two wires (running to fuse power and brake switch) and then power on the single wire running to TS only when the hazard switch is in the off position. When I pull the hazard switch there is no power running to that wire. Is that how it should be?
 
4spdragtop said:
When does it have power on both sides? Not sure but I think it matters.
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Ok, so strangely I double checked the brake switch at the pedal and I must have lost my mind the first check because now I’m clearly getting voltage going into it (from pink wire) but only .04volts on the other other side of the switch when I press the pedal (no voltage when pedal isn’t being pressed)! So is it a bad switch? Also would this bad switch cause the hazards not to work? That part seems strange to me as I wouldn’t think that would effect it
 
If you are not getting 12V going in and out of the switch when it is "closed", I'd assume the switch is bad. Double check this by testing for continuity(ohm meter) with the switch "closed", meaning pressing on the pedal.

Do you have an extra known-to-be-good emergency flasher you can throw in there.
 
dodgemahal said:
If you are not getting 12V going in and out of the switch when it is "closed", I'd assume the switch is bad. Double check this by testing for continuity(ohm meter) with the switch "closed", meaning pressing on the pedal.

Do you have an extra known-to-be-good emergency flasher you can throw in there.
Click to expand...
So I double checked the switch and I’m actually not getting power going to white wire out of switch with pedal pressed or not pressed. But I ran a number wire to get power to the white and still no brake lights and yes I swapped out hazards flasher and still get nothing. So I’m kinda stumped cause clearly my switch isn’t working but again after I ran 12v directly bypassing the switch the lights still did not come on. Key was on by the way
 
dan0340 said:
So I double checked the switch and I’m actually not getting power going to white wire out of switch with pedal pressed or not pressed. But I ran a number wire to get power to the white and still no brake lights and yes I swapped out hazards flasher and still get nothing. So I’m kinda stumped cause clearly my switch isn’t working but again after I ran 12v directly bypassing the switch the lights still did not come on. Key was on by the way
Click to expand...
I meant a jumper wire not number wire above
 
Key doesn't have to be on. Was there 12 volts on the pink wire going to the switch? Try replacing the switch. Dirt cheap on rock auto. I saw one that was $3.00.
 
You can jumper it rather than replace it to test. If there is truly voltage on both sides of the BL switch that should power the brake lights. Most common problems of this sort are in the hazard switch, I'd assume contacts in the switch walking around.

Make a table of your TS switch colors so you know what they should do and when. You could also jumper 12V to the white brake switch wire, and with hazards off and TS switch centered, that SHOULD power the brake lights for test.
 
dodgemahal said:
Key doesn't have to be on. Was there 12 volts on the pink wire going to the switch? Try replacing the switch. Dirt cheap on rock auto. I saw one that was $3.00.
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Ok I replaced the switch. Here is what I have discovered. If I touch a probe to the pink lead wire in to the switch I get 12 volts. When I touch the probe to the terminal with the white wire attached I get .04 volts. Here is the strange thing, if I disconnect the white wire from the tab and probe the tab (terminal) I get 12 volts! As soon as I attach that white wire the voltage drops to .04 volts.. I don’t understand the system so not sure if this is correct or not. My brain doesn’t compute how the voltage goes away when I connect the white wire
 
Follow up with 67Dart273's suggestions stated above. Keep poking around, keep testing; you'll figure it out. That's what I do. Walk away when you get frustrated and come back with a fresh clear mind. You'll get it. Keep us up to date.

Edit: the white wire goes to the TS switch. It's time to start examining that, me thinks.
 
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dodgemahal said:
Follow up with 67Dart273's suggestions stated above. Keep poking around, keep testing; you'll figure it out. That's what I do. Walk away when you get frustrated and come back with a fresh clear mind. You'll get it. Keep us up to date.

Edit: the white wire goes to the TS switch. It's time to start examining that, me thinks.
Click to expand...
That’s exactly what I was thinking. Whatever takes place in the column where that white signal wire goes to then send power(I think through dark green wire) to the lights is not working.
 
dodgemahal said:
Follow up with 67Dart273's suggestions stated above. Keep poking around, keep testing; you'll figure it out. That's what I do. Walk away when you get frustrated and come back with a fresh clear mind. You'll get it. Keep us up to date.

Edit: the white wire goes to the TS switch. It's time to start examining that, me thinks.
Click to expand...
I pulled the steering wheel and I’m looking at the whole switch assembly in the steering column. Looks like 3?screws to remove but then I don’t know how I will be able to run the new one’s wires and plug through the mid section of the column. Maybe I have to reve that too

IMG_0547.jpeg
 
Someone else on this forum can get specific. I have not replaced one in years, so I don't remember. Get a factory service manual if you don't already have one. Do some testing first before going to all that trouble.
 
67Dart273 said:
You can jumper it rather than replace it to test. If there is truly voltage on both sides of the BL switch that should power the brake lights. Most common problems of this sort are in the hazard switch, I'd assume contacts in the switch walking around.

Make a table of your TS switch colors so you know what they should do and when. You could also jumper 12V to the white brake switch wire, and with hazards off and TS switch centered, that SHOULD power the brake lights for test.
Click to expand...
So I did run a jumper wire on the brake switch white wire. This is what is happening that puts my brain in a pretzel.. it’s difficult to even explain but if I run twelve volts directly to the white wire the voyage gets canceled out. Call me crazy but when I run 12 volts to the tab with the white wire, I test it with my probe and I get .04 volts on the tab with white wire connected. But as soon as I remove the wire the tab shows 12 volts! What am I missing?
 
I had a left front turn signal issue on 67 cuda. A combination of loose bulkhead connection AND steering column connector with the long (deutsch I think) connectors. My hazard is on dash, while yours is on column. The 3 small Phillips screws(thru plate) hold the switch down.
Also wiring on column underside needs some slack. Double chk all connections before removing that switch. Rabbithole!
 
OP; try flipping on your hazards and apply a little pressure to the bolt that holds the indicator lever on The switch halves pivot around) and see if you get them to work. Don’t touch your brakes at the same time! The test may burn your bulbs out. There is some functionality in there that stops the brake lights from canceling your blinker when both are on at once. All that to say; I think it’s the switch
 
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