still trouble w/ tail lights

[67Fleet]

well, I'm still puzzled why my tail lights are not functioning properly. The blinkers both work, but the tail lights and brake lights don't. I've checked the entire fuse panel with a test light and all are good. Replaced both relays. Checked both bulbs out back. I just don't get it. Any other ideas? It shouldn't be a ground if the blinkers are working right? Please help!! Otherwise I'm gonna take it in saturday morning to an auto electrical place and the guy told me it'll probably cost me $125.00!!!! I've gotta get it fixed before the Rod Run in daytona thanksgiving weekend. I'm running outta options.

[redhead69]

Rear harness in good shape?

[redhead69]

I'm just brain(mush)storming here..
Isnt there a brakelight switch? Is it stuck?

[67Fleet]

Originally Posted by redhead69

I'm just brain(mush)storming here..
Isnt there a brakelight switch? Is it stuck?

dunno, but even if it was, wouldn't my tail lights work when I turn the running/headlights on?

[redhead69]

yeah your probably right.. sorry.

[69TowRig]

The stop lamps and blinkers use the same wire from the dash harness and thus the same filament on the bulb. The tail lights use the second filament in the rear bulbs.

Knowing this, check your stop lamp circuit first to see that the switch works.
Then check to see that you are getting running light power back to the tail lights. If your license plate light works when you put on the parking lights, you have power getting to the rear of the truck for the running lights, it's just not getting to the tail lights. Unplug and plug in the gauge circuit board connector, mine was not making good contact and causing a similar problem.

[Longhorn Man]

The brake lights will either be the brake light switch... or the turn signal switch. 99% likely to be one of the two.
The tail lights... pull a bulb and see if you are getting power.... heck, just replace a bulb with a new one to rule out the dummy mistake. (yes... I've spent hrs troubleshooting only to discover the bulbs were bad)
If the bulbs are good, I say look under the bumer first, the harness was probably hacked up for a trailer plug. Look at the brown wire for bad connections or breaks in the wire.
Do your dash lights work?
how about the front parking lights? (which will only work in the parking light position, and turn off when the headlights come on)

[69TowRig]

Originally Posted by Longhorn Man

I say look under the bumer first, the harness was probably hacked up for a trailer plug.

How could I forget!! Mine had three separate spots where the harness was hacked over the years for trailer lights. I spent a couple evenings just patching the harness. Definitely check that.

[jimfulco]

Tail-light fuse?

[67Fleet]

Originally Posted by Longhorn Man

The brake lights will either be the brake light switch... or the turn signal switch. 99% likely to be one of the two.
The tail lights... pull a bulb and see if you are getting power.... heck, just replace a bulb with a new one to rule out the dummy mistake. (yes... I've spent hrs troubleshooting only to discover the bulbs were bad)
If the bulbs are good, I say look under the bumer first, the harness was probably hacked up for a trailer plug. Look at the brown wire for bad connections or breaks in the wire.
Do your dash lights work?
how about the front parking lights? (which will only work in the parking light position, and turn off when the headlights come on)

Longhorn, the dashlights DO NOT work either, but the front parking lights DO work. I checked the yellow wire that goes to the brake light switch and it is getting 12V power. I don't see where I can get to the white wire to the column. I can't find a white wire, plus the cab has been repainted by PO and he didn't take everything out so there's overspray coating some of the wires making it hard to tell what color they are.

[pjmoreland]

Make sure you have 12 volts on the orange wire that runs from the fuse panel to the brake light switch. Then make sure you have 12 volts on the white wire that runs from the brake light switch to the steering column when you press the brake pedal. If both of these things look good, then I'm guessing you need a new turn signal switch in your steering column.

[truckdude239]

when i did mine my turn singals would work but the brake and tails nope turns out that i had to take an wire brush and clean the fenders where the bucket of the lights sit because they wheren't grounding right and now they work great

[nutsforchevys]

[truckdude239]

i also rewire from the plug back lol and had the trouble that was the last thing i tried cleand the grounds a boom everythign work

[re1]

I had the same problem after replacing my bed mount bolts,
it ended up being a grounding problem (bed to frame).
My turn signals worked but were not as bright as usual.

[Longhorn Man]

A bad gouund makes no sence... but it won't hurt to look.
The not as bright signals with a bad ground is back feeding into the parking light circuit
a coupl ehave said look at the fuse... in the original post, he stated that he checked every fuse and then replaced both relays..... I'll asume the relays in question are the flashers, which they were working fine already.

[67Fleet]

Originally Posted by Longhorn Man

A bad gouund makes no sence... but it won't hurt to look.
The not as bright signals with a bad ground is back feeding into the parking light circuit
a coupl ehave said look at the fuse... in the original post, he stated that he checked every fuse and then replaced both relays..... I'll asume the relays in question are the flashers, which they were working fine already.

Correct. Well, I'll check the ground with a wire brush since that's pretty simple. My hazard lights don't work at all front or back, but I'm assuming that is because of the switch on the column, and who knows what I'll find when I tear apart that thing as the truck was originally an auto but now is a 4-spd man. on the floor.

Truckdude, where exactly did you hit the fenders w/ the brush?

[GRAYGHOST]

I have a friend with 67 stepside. He kept blowing fuses. His brake lights and tail lights wouldn't work, the blinkers would. We ended up checking all of the harness from the fuse box to the lights. We found some small nicks the wire. I don't know if that helps. If thats not the problem, then take a wire and conect one end to the light (where it mounts) and the other end to the frame. This will eliminate a ground problem. Good luck

[truckdude239]

when you take the colored lences off then un screw the metal bucket where the metal bucket sits on the fenders in the hole shoot mine had primer shot in them

[brownk]

I had similiar problems with my lights and it always came back to a ground issue....

Kurtis

[67Fleet]

OK, pulled the steering wheel and took a look at the switch. Is there any way to tell it is bad? It was super easy to get to, and I had it partially out of the column but didn't want to completely disassemble it, nor did I know how so I put everything back together.

Note #2: When the headlights are on, and then I turn either right or left blinker on, the blinkers blink at half their normal speed than if the headlights are not on. Maybe this narrows down the possible answers?

Note #3: Hazard lights do NOT work. After I put everything back together I pushed in the hazard switch and I heard the relay ping once but I couldn't get it to ping again no matter what I tried.

Note #4: Dash lights still don't work, exdept the blinker indicator lights and the blue bright light signaling the bright headlights are on.

[69TowRig]

I'm also starting to suspect the problem is in the turn signal switch. The white wire can be accessed at the turn signal harness connector.

[pjmoreland]

The white wire for your brake lights runs from the connector on your brake switch (in the same connector as the orange (yellow) wire). It then runs through the harness to the "C" shaped connector that is dangling out of your steering column. The white wire is at one end of the column, right next to the light and dark green wires that come out of the column to feed your brake/turn signal lights. If you have power at the "C" shaped connector on that white wire when the brake pedal is pushed down, and your brake lights don't come on, I'm pretty sure your turn signal switch is worn out.

You might want to take a look at the brass contact plate inside the turn signal switch to see if all the little bumps are worn off of it. To gain access to the brass contact plate, you'll have to remove the screw that holds the turn signal lever in place, remove the two long thin leaf springs on the right that help center the switch when your turn signals are off. There are two annoying plastic latches that you have to flex out of the way. Then you should be able to pull the top half of the switch off. The brass contact plate will come off with it. I had a '69 that had all kinds of crazy problems with the lights because the brass contact plate was totally worn out and was shorting various circuits together inside the turn signal switch.


#4: There's a black wire coming out of the connector that plugs into the back of the gauge panel. If I remember correctly, the black wire is the ground path for the gauge panel lights. It is supposed to be clipped to the metal part of the dash. You might want to check to make sure the wire is clipped on. If it is clipped on, try wiggling it around a bit to help it bite in, especially if the back of the dash has been painted.

[67Fleet]

OK,well I have a turn signal switch coming in to the local parts store this afternoon. I'll get going on putting it in tonight or tomorrow morning. If that's not the problem, I'm going to blow a fuse of my own. I HATE ELECTRICAL PROBLEMS!!!! Is there anything I should know about replacing the switch? Any pointers? Is it pretty much plug and play?

[stueber68]

Hey! Check Out The Plug Above The Accelerator Where The Rear Lights Go Through The Firewall. I Am Wondering If That Didn't Get How And Expand A Little Bit, Causing A Short. Seems Like Everything For The Front Is Working Right. The Only Other Thing I Would Say Is To Make A Test Ground Frome The Body To The Frame.