Another stupid brake light wiring thread...

[Dr. Wombat]

Sooo...

I should start by saying I've read on here as much as I could...

No brake lights.

The pedal switch tests good.

There is 8 volts on one of the black why yellow wires going to pedal switch. (Any ideas as for why 8?)

My main question I suppose is at what location/connector does this wire turn from black/yellow to green yellow?

I feel seriously stupid right now... Any help appreciated.

[Hardway]

Can you post the year and model of your Z?

[Dr. Wombat]

Sorry...

Car is a 1974 260z, manufactured 12/73

[Willoughby Z]

Download the FSM.

Check the BE chapter...

XenonS30

[SteveJ]

Sooo...

I should start by saying I've read on here as much as I could...

No brake lights.

Have you measured the voltage at the brake lights themselves?

The pedal switch tests good.

How did you test the switch?

Here is how I suggest you test the switch:

1. Disconnect your battery negative.

2. Disconnect connector C-2. (You'll need to refer to the FSM BE section to find it.)

3. Put your multimeter on the lowest resistance scale (if it's not autoranging).

4. Touch your leads together firmly to see what they read without anything else.

5. Press the brake pedal and measure resistance across the switch.

6. Subtract the reading from step 4 from the reading in step 5. It should be less than 1 ohm.

(I'm picky. Good isn't a number. )

There is 8 volts on one of the black why yellow wires going to pedal switch. (Any ideas as for why 8?)

Reasons for 8 volts:

1. Bad switch

2. Bad technique with the meter

3. Bad ground or poor grounding point selected when you measured

4. Bad meter

My main question I suppose is at what location/connector does this wire turn from black/yellow to green yellow?

I feel seriously stupid right now... Any help appreciated.

Where did you see the wire turn to green/yellow? Are you sure it was green/yellow? Green/white is for the parking lights, and you could get confused with old/dirty wires.

The brake light circuit is on BE-13. Detail on the stop switch is on BE-27.

[Dr. Wombat]

The yellow/green the harness lead attached to bulb and conituing from body harness into quarter panel.

Black/yellow is at pedal switch.

The 8 volts I'm metering is pre-pedal switch to chassis on my fluke, which I know how to use...

[SteveJ]

The yellow/green the harness lead attached to bulb and conituing from body harness into quarter panel.

Black/yellow is at pedal switch.

The 8 volts I'm metering is pre-pedal switch to chassis on my fluke, which I know how to use...

Assuming you have 12 VDC to chassis on both side of the fuse, there could be corrosion or poor connection at connector C2 or the lead on the switch. A PO could have hacked the wiring, too. Pull the fuse and measure resistance between the fuse box and the switch.

What about the other diagnostics I suggested?

[Dr. Wombat]

Starting to confirm my Z has been hacked up by PO. There's all sorts of random stuff not on diagrams(clearly the work of methamphetamines... ), in addition to clear instances of PO wiring AROUND the harness/adding bits and pieces/leaving disconnected crimp ends with no mate...

I'm in Ventura CA(93003). Anyone know someone knowledgable in the area I can take this too?

I feel this is getting out of my league and is a safety concern. I'd rather it not catch fire in my driveway :/

[SteveJ]

That's why you carry a fire extinguisher...Don't ask.

Since you come across as having some electrical aptitude, you could try contacting Oliver at Z Specialities. He might have a wiring harness that you can buy.