67 F-100 no brake lights

[oddball]

Well I'm still having problems with my brake lights not working. The last time I posted I had installed a junk yard turn signal switch which gave me turn signals, instrument lights, dome light, and parking lights. I didn't have brake lights or hazard lights. I bought a new switch from Dennis Carpenter and I still don't have brake lights. In fact the red with black stripe wire doesn't have power at all now. The bulbs, flashers and hazard switch are new also. The brake light switch is good. I'm almost 100% sure the switch is wired correctly because I tried every possible way to connect the wires and the wiring diagrams are totally worthless. Ive checked everything I could think of a million times and I'm ready to give up and blow this truck to pieces. If anybody has an idea it would be great

[AlleyCat]

Oddball this likely the dumbest answer you'll get but have you checked the fuses? If memory serves me correctly the stop lights and flashers are powered from the same fuse. Glass tube fuses can look okay but be broken in the end caps where it can't be seen. It's also possible that the feed wire to that circuit is corroded or broken in the back of the fuse box.

[oddball]

No answer is dumb in my opinion but I have checked pretty much everything. The red/black stripe wire did have power before I replaced the switch, so maybe the new switch is bad? I really doubt it. I would like to be able to check the switch before I throw anymore money away for new parts. I put a hot wire on the rivet for the red/black wire, while It did make the brake lights come on there still wasn't any power in the wire.

[fordman]

i'mjust going to run through this. check the fuse. check the bulbs. check to dsee if you have power to the socket when you push the brake pedal. bypass the brake pedal switch with a piece of wire and see if they work. check all wiring in the column and the plug at the bottom of the column. check all the wiring undert he truck to make sure it is all intact and connected. do the center of the socket connectors look worn down. maybe they aren't connecting properly to the bulbs. find out where the power start and where it stops. that is where the problem is. maybe the new switch is bad? or it is wired differently than the original was.

[oddball]

Ive done all those, there isnt power at the brake switch plug when the pedal is pressed or the plug for the hazard switch. All the wiring and plugs look good, bulbs work because I have turn and parking lights. Im sure the turn switch is wired correctly but I dont know for sure. The wire colors match the harness colors exactly so I connected them that way. The turn signals and parking lights only work the way I have it connected now, Ive tried 50 possible ways of connecting wires. So either the signal switch is wired wrong, the switch itself is bum, or like fordman said Ill have to find were the power start/stops

[oddball]

Oh I do know that with the old switch, even though the brake lights didnt work,I had power to the red/black stripe wire

[fordman]

i think you have a loose contact in either the tss or the plug at the bottom of the column. that is what i am seeing in my book.

[Wes]

Check the wiring dia for the 69 late 67 (like mine) matched the 69 dia better. Power from the fuse to the emergency flasher 1st, then to the brake light switch. From the brake light switch to turn signal switch. The same circuit from the brake light switch, to turn signal switch, also runs to the emergency switch. If the emergency switch is close the brake lights may not work.

[Thunderfoot]

At the Brake light switch: Check the Red wire for power with a TEST LIGHT it should have power even with the key off. If this wire has NO power then go to the fuse box and check the 20amp fuse for the stop and emergency lights to make sure the fuse and fuse holder have power on the right side (see picture below). If they do then unscrew it from the firewall so that you can check the back side. On the back side you will see a Blue/White striped wire (according to the 67 diagram) check that it has power on it. (see picture below of my 69 it is a Red/White striped wire) If it doesn't then there is a problem with the fuse holder or where this wire is connected to the fuse holder. (I just had this same problem with my truck last week and it was the fuse not making good contact with the holder)
If you do have power there then you will have to follow this wire to the Emergency flasher as it turns to a Red/white striped wire there. At this same connection at the emergency flasher, it has the Red wire that goes to the Brake Light Switch. You will have to find out where it is loosing power at in this line.

If this Red wire at the brake light switch has power then press the brake pedal and check the Red/Black striped wire on the other side of the switch, if it has power then check the Red/Black striped wire at the connection for the TSS and then at the top of the switch to see where it is missing.

EDIT: I changed a couple of wires I had listed as Red/white to Red/black where they change after the brake light switch.

Click pictures to enlarge.

[oddball]

Ok this is good info guys thank you, I will check this stuff tomorrow and report back

[AlleyCat]

I was hoping you'd chime in Shayne. I know what to test and how to test it but explaining it is a whole different thing. I've had my share of contact problems with glass tube fuses.

BTW, here's a little electrical troubleshooting trick that may come in handy for someone. When troubleshooting problems one of the most frustrating things is to test a wire for power with a test light or meter, the test shows there is power but whatever the wire is connected to doesn't work. Most folks assume that the light or other part has failed and replace it. The frustration sets in when the new part doesn't work either. Before you get upset with a vendor for selling junk parts try one more thing. Go back to that power wire and recheck it using a headlight as a test light. Sound crazy? Maybe so but it works and here's why. A regular test light uses a few miliamps. A mulimeter uses even less. Both can show the presence of voltage but they can't draw enough amps to load the circuit. Automotive wiring is made from stranded wire. Stranded wire is many small wires wound together to form a larger one. Corrosion and mechanical damage can break strands leaving the wire unable to carry enough amperage to supply the circuit. All it takes to power your test equipment is one or two strands so you assume the wire is good. A headlight requires much higher amperage so you can load test the wire. If the headlight won't light but the test light does your problem is with the wire. You can buy inexpensive test leads at any electronics store to use a headlight for testing.

[oddball]

Well I checked the fuse and fuse block. Eerything was good had power at all contacts. I pulled the fuse, looked at it, put it back in and now I have brake lights. Go figure. The truck is pretty much squared away now, thanks to everyone for the help

Robert

[Lar4t9r]

I was hoping you'd chime in Shayne. I know what to test and how to test it but explaining it is a whole different thing. I've had my share of contact problems with glass tube fuses.

BTW, here's a little electrical troubleshooting trick that may come in handy for someone. When troubleshooting problems one of the most frustrating things is to test a wire for power with a test light or meter, the test shows there is power but whatever the wire is connected to doesn't work. Most folks assume that the light or other part has failed and replace it. The frustration sets in when the new part doesn't work either. Before you get upset with a vendor for selling junk parts try one more thing. Go back to that power wire and recheck it using a headlight as a test light. Sound crazy? Maybe so but it works and here's why. A regular test light uses a few miliamps. A mulimeter uses even less. Both can show the presence of voltage but they can't draw enough amps to load the circuit. Automotive wiring is made from stranded wire. Stranded wire is many small wires wound together to form a larger one. Corrosion and mechanical damage can break strands leaving the wire unable to carry enough amperage to supply the circuit. All it takes to power your test equipment is one or two strands so you assume the wire is good. A headlight requires much higher amperage so you can load test the wire. If the headlight won't light but the test light does your problem is with the wire. You can buy inexpensive test leads at any electronics store to use a headlight for testing.

Alleycat:
Outstanding advice to those of us that are electrically challenged!