No Brake Lights, Help!

[Zs-ondabrain]

Now that the brakes don't come on permanantly, try the turn signals. If the turn signals work and the brakes don't, the problem could be in the Metal turn signal switch. They warp over time and overheating can also cause the warping.

Expose the T/S switch, press on the brakes while connecting the green/yellow and white/red wire on that metal switch box. If the brakes work, then the metal box is the problem.

Let us know what you find.

Dave.

[beezee]

Looking at wire diagram circuits for a 74 car illustrates separate fuse circuits for brake and tailights, are earlier cars the same? May have a fuse or power feed problem at fuse block

[JimmyZ]

. I switched the green/yellow wires around on the brake switch, but no luck. I will try putting the original brake switch back in tomorrow

1974 is probably different.

Unplug the two GY's at the brake light switch and run a jumper between them. If this doesn't turn on the brake lights then jostle the brake light fuse a bit. (Twist/shift it to break through any corrosion) You may not need to replace the BL switch. I'm sure you did it right but is the switch adjusted right?? Try a mulimeter on the leads of the BL switch. (Check for continuity when the pedal is depressed) You should have voltage at one of your GY wires at the switch.

Swapping GY's won't have any effect since it's a simple switch. There are some other wires with plugs in the vicinity which could have been plugged in. That's why I mentioned it.

Edited November 9, 2008 by JimmyZ

[lonetreesteve]

I tried switching out the turn signal switch as Dave had recommended, but it didn't make a difference. After that, when I turned the lights on the left rear brake light came on also. I tried a number of the other suggestions you guys made, but nothing seemed to do the trick. I wonder if I just need to buy some new tail light harnesses somewhere. I really all of the help you guys gave me.

By the way, I took a picture of 2 wires under the steering column, 1 red wire and 1 ground wire. I assume these are for fog lights or are they for something else?

[EScanlon]

R & B = Key-In Warning Buzzer circuit.

In one of the pictures above, the main black ground going to the combination switch is not connected. Have you corrected that? You have swapped the switch out, but an incorrect assumption on how the wires connect can simply replicate the problem time and time again.

The "Blue" wires (L, LY, etc) are for the wiper and washer, but I don't recall a Black/Yellow at the steering column.

The combination tail lamps use 3-1156 Bulbs and only ONE 1157.

FWIW

E

[Zs-ondabrain]

Black yellow is the starter wire on the ignition, ignore it.

Do the parking lights come on when you hit the brakes?? Pay attension next time you hit 'em. If the parking lights come on with the brake lights, it's definately a short.

[EScanlon]

If that Black/Yellow IS for the Starter, then he has some serious problems.

The pictures show the B/Y connected to something other than the ignition switch. You can readily see the ignition lock with the B/Y wire not connected to the backside. (Also, aren't all 5 wires going to the Ig. Switch in a single 6 wire connector?)

Like I mentioned previously, the "blue" series of wires at the column are typically for the windshield wipers and washer circuits. If that B/Y IS for the starter, then what does he do, toggle the Windshield Wiper switch to start his car?

I'm relying on the wire colors in the harness and not the ones coming from the comb. switch, as I've seen discrepancies with respect to the schematics color legend more often with the comb switches than with the wiring harness. The same discrepancies happen with regards to individual component harnesses (tail-lights, instruments, etc.). But this doesn't mean harness errors don't happen.

But before we go on a wild chase, I'm still betting it is something quite simple especially if it just started happening. Electrical wire connections don't suddenly decide to reconnect incorrectly, except for a short circuit, and that doesn't involve plugging and unplugging connections.

That being said, it is more than likely either a broken hazard switch (if it "just suddenly started") or a misconnecton (if it occurred after a "repair" or "upgrade"). That's why I asked what the last thing he had done was.

E

[lonetreesteve]

To tell you the truth, I don't know if the brake lights ever worked on this car. I just got it on the road a couple months ago after the refresh and haven't driven it that much. My daughter told me when driving behind me the other day that the brake lights don't work. Also, EScanlon mentioned the wipers, which I completely forgot about - they don't work either! EScanlon might be on to something here. I've got to run to work now, but I'll check back in tonight.

Thanks again guys.

[EScanlon]

Reviewing older diagrams it is possible that that B/Y wire actually goes to the Washer motor. Older diagrams show the Washer motor as having a B/Y wire that magically transforms to a Blue/Red (L/R) at the firewall or thereabouts. That it makes it all the way to the steering column switch area is just one more anomalie to note in the wiring schematics I've seen.

To double check that your brake light circuitry is functional, jumper the two Green/Yellow wires at the Hazard Switch connector and then join the two G/Y wires at the Stop Light Switch. With that shunt and switch bypass your brake lights should be both on. If they are not, or only one, then your problems are NOT in the HAZARD Switch. We need to check the comb. switch next.

Next re-connect the Haz. Sw, and while you maintain the Stop Light Switch shunt, now at the combination switch cross connect the Green/Yellow wire with either/both the White/Red and the White/Black. When you do so you'll get either the Right (W/B) or Left (W/R) or both lights depending on how you've cross-connected. If you DO have the lights then your problem IS in the Combination Switch. If you still do NOT have lights, then your problem is in the wiring to the back.

This should get you back on track.

Check your grounds at the back, they're often overlooked.

HTH

E

[KenshinX]

Was the problem ever resolved Steve? I am having the same problem with my 260z. Although, I don't know if they ever worked since I bought the car.

[biddljj]

I found this thread whil elooking for a definition of where the gounds are located in my 72 240Z..... Good discussion...

Jay

Not just a Z - ZDisease

[Frankensteinz2]

I had problems getting my brake lights to work, and using this thread i was able to narrow the search down to help me locate the problem. Thanks