Red mystery wire

[boomboom]

All,
I have been fighting an odd problem for a while now with my 77 Targa, 3.2 DME. Symptoms have been constant current draw of around 2 to 3 amps. Yes you heard correctly. Wire was on the bottom of fuse 17 and when removed current draw goes away, but left brake light does not work or is barely on. When connected to bottom of fuse position 11, brake light works, but engine will continue to run.

Has anyone seen this wire? Red with a silver or light green stripe running the length of the wire.

Thanks,
Alan

[Dave Colangelo]

First off I assume it was a conversion as there was no 3.2 or DME in the 77, that would have a 2.7 CIS I believe. It sounds like if this is the case there may be a wiring mistake in the harness some where. I would first check the brake light and see if there are any visible shorts. It sounds like there is a short some where to ground in some capacity. I would check out the harness for visible burnt shorts or wire casings that show signs of melting. What is the voltage at the brake light in both cases?

Regards
Dave

[boomboom]

Have not measured voltage at the brake light and should also check the wiring. Yes this was a conversion done around 2005. I bought the car after the conversion and have had the constant drain until locating the wire on fuse 17. Funny thing is it works on position 11. All other multi color wires have stripes around them, this is the only wire with the stripe length wise.

Hopefully will check all wiring at the lights this weekend and check voltage.
Thanks,
Alan

[Joe Bob]

Move the brake light to another unused circuit and check it's ground.

[javadog]

Going off of memory here, but I think in 1977 "striped' wires didn't have a continuous stripe in them, but an intermittent one. Therefore that wire is not original to the car, so looking at a wiring diagram is not going to help. You're going to have to trace that wire to it's other end to see what it is. That fusebox is not original either and most of the wires I see in that picture aren't original, so you're going to have quite an adventure.

JR

[boomboom]

Hey JR,
Your memory serves you right, no continuous stripes on 77 wires. Yes this is an updated fuse panel from Fred Cook that is great panel. All problems were there and more prior to the fuse panel upgrade. I will need to troubleshoot and measure continuity and voltages from the tail light wires and do lots of tracing.

Thanks again for all of your suggestions.

Alan

[304065]

Alan, that is not a German wire running across your gas tank filler, it's British or USA, due to the straight, not spiral tracer.

[boomboom]

That is awesome to know, thanks. I am going to try and trace it physically and ohm out. Nice to know it doesn't belong or was original.

[suprxman]

I had a no "right rear " lights at all problem. Finally..... behind the right rear shock mount in the engine compartment found ALL the wires frayed so badly that none were attached to each other. Spliced em and problem solved. Don't know why it didn't start burning.

Maybe yours has just started separating.

Anyone else seen this?
Good luck.

[fred cook]

Originally Posted by boomboom

All,
I have been fighting an odd problem for a while now with my 77 Targa, 3.2 DME. Symptoms have been constant current draw of around 2 to 3 amps. Yes you heard correctly. Wire was on the bottom of fuse 17 and when removed current draw goes away, but left brake light does not work or is barely on. When connected to bottom of fuse position 11, brake light works, but engine will continue to run.

Has anyone seen this wire? Red with a silver or light green stripe running the length of the wire.

Thanks,
Alan

Fuse #11 (should) have a green/blue wire coming off the bottom of the fuse going to the brake light switch. From the BLS, a black/yellow wire runs back to the left brake light and then across to the right brake light. If the right light is showing up bright but the left one is not, it will almost have to be a bad ground at the left taillight assembly, or a bad wire running into the brake light socket. If you can get that analyzed and fixed, then you will have no need for the added red wire. That will solve both the light problem and the shut off problem! By the way, your fuse panel installation looks quite nice! Good job on the wiring.

[boomboom]

Hey Fred,
Yeah the panel came out great and many of the issues are gone. Still owe you pics of the install. The shutoff problem was the red wire with the silver tracer. It is now totally isolated and disconnected. I have narrowed down to the following:
1) Brake lights only work when headlights are on, but only the right, not the left.
2) Tail lights work fine on both until the brake is applied, then the left taillight goes dim
3) I believe the harness must have been changed for the 3.2 DME motor. There is another thin black wire coming from the larger harness to the fuse panel that seems to control the DME? Motor will not start unless it is connected. Currently is connected to B16.
Will have to go to the taillight assy. and check wiring, grounds etc.

More tomorrow. Beer time.

[boomboom]

First thanks to everyone for your help and suggestions. The last problem with the brake lights is fixed.
1) There was an open wire from the left taillight assembly. Had to install a new wire from the fuse panel to the taillight.
2) The mystery red wire does not appear to be needed and was the source of the 2+ amp draw.
3) The new fuse panel from Fred Cook is awesome. It fixed a number of gremlins such as the courtesy light issue. The key buzzer even works now.
4) Engine not stopping after turning key off also fixed. Mystery wire caused this.

This car had many wiring issues when I got it due to the harness change for the 3.2 DME motor. Additionally the old fuse panel had some corrosion on many of the brass contacts. Really nice to have blade fuses now.

Pics below show the new panel with all wires labeled. Had to add extensions to many wires as seen around the Fuel Pump Relay. The new panel has relays for the headlights that prevent the higher current draw thru the switch.

Time to start driving without concern of a dead battery.

Alan