[Mr. Sp0rk]

hey guys, I have a 67 el camino and here is my problem:

I was poking around with the multimeter yesterday trying to find out why my turn signals work, and my brake lights and hazards do not. I first tested the brake light switch. It seems ok. I has orange and white going into it (as the schematic shows). I followed the orange white into the column harness, and out. When tested the voltage on these two wires (orange has + white as -) with no brakes they have ~10.5 V running through them and with the brakes applied they have 0 V. (I believe that is because they become the same charge, thus voltage difference is 0, am I correct?) Anyway, these wires are for the dome light as per my diagram. Yet, after lots of testing they are the only wires which change charge with the brake switch. I currently have the tail lights hooked into the rear harness as per the diagram (yellow : stop/turn. brown: tail) Do I have a bad turn signal switch? Do I have a bad ground somewhere? (if so, where would you guess?)

I am running out of ideas for this problem, and it is the driving force behind "some people" wanting me to sell it. I would greatly appreachate it if any help could be lent on the issue, you might just save my truck.

Thanks alot, not just for any responses, but for all I have learned thus far in reading this forum.

Jeff

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1967 El Camino - 402 Big Block
1985 Porsche 944 (maybe)

 

[John_Muha]

Think you may be looking at the circuit a little wrong. Don't measure the voltage difference across the switch. Measure each side to a good ground. Measure the input orange (+) to a good ground. Should be 12 volts. Measure the brake switch output (pushing on the pedal), the white wire (+) to a good ground. Should have 12 volts. The output wires are yellow and green from the turn signal switch for the brake. Should have 12 volts on each one to a good ground while pressing on the brake.
Brown is the tail (running) lamps. Its power comes from the headlight switch.

 

[Mr. Sp0rk]

UPDATE..

I was poking around with the ol' mutlimeter last night and found out some
more interesting things.

(I am measuring from the harness that changes from wires into the ribbon
cable before it passes under the carpet)

The orange wire is hot with ~10.5 V (12V) when properly grounded on a good
ground. When i depress the brake pedal this drops to 0 V I believe this
wire should stay hot, or am i mistaken? I tested the white wire in the
harness (which should have 12 V when the brakes are engaged) and it has 0 V
with or without brakes. EVERY OTHER WIRE in the harness is dead. Here are
my suspects...

-a bad ground
-a bad turn signal switch
-a bad brake switch

Should i test the wires at some other point? am i thinking about this
wrong? thanks alot for any help.

Jeff

 

[John_Muha]

Stay up on the brake switch.
1,Measure the brake switch orange wire to a good ground.
2, Stay on the orange wire. Push in the brake pedal. Does the voltage drop to 0?
3, Stay on the orange wire. Release the brake pedal. Does the voltage come back up?
4, Try this a couple of times. If it repeats (low volt/high volts) like I said, it's an easy fix (hopefully).
You probably have a dirty brake fuse clip connection. Able to see voltage but can't pull any current through it. Replace the brake fuse, clean up the fuse clips and try it again.