What is the green with black stripe wire under the hood.

[lts70]

What is the green with black stripe wire under the hood? Had to redo the heads On my 1987 TBI 454. Have a green wire with black stripe that I’m not sure where it goes. Any help would be greatly appreciated.

[RotaryRocketeer]

Single green wire on my truck is the tach output.

[blindbug]

Idiot lights, or gauges? Engine Size?

I have idiot lights on my 86' and a 350 v8. One of the green wires under my hood connects to the temperature sending unit/switch located on the driver's side between my exhaust manifolds in the front. It has a black adapter on the end that slides onto the temperature sending unit (which looks like the head of a nail).

[Dead Parrot]

Green wires in that location are usually one of the following:
Temp gauge or idiot light to sender
AC compressor clutch
Idle comp solenoid
Electric choke

The last two probably don't apply to a TBI.

I think some AC compressors had the high pressure cut off switch in or on the compressor instead of over by the AC box.

[hatzie]

HPCO, if present is an owner/builder add on.
LPCO is on the accumulator. Solid green wires.
THe above run to the AC compressor.

The only GREEN/Black under the hood in 1987 is one of four wires to the IAC. Specifically Circuit 444 from the ECU to IAC stepper coil B...

Are you sure it has a black tracer stripe and it's not just filth?

[TKCR]

Looks like the Temp Sensor wire. Mine was laying lose in the engine room, because the previous owner had put an aftermarket temp unit in. I put a heat resident loom on it, since the temp sensor is right there by the headers. The original plug was melted, so when I put a new one on, I thought I would try and help protect it from the heat.

[hatzie]

Originally Posted by TKCR

Looks like the Temp Sensor wire. Mine was laying lose in the engine room, because the previous owner had put an aftermarket temp unit in. I put a heat resident loom on it, since the temp sensor is right there by the headers. The original plug was melted, so when I put a new one on, I thought I would try and help protect it from the heat.

The temp gauge sensor or dummy light switch wire is solid green with no tracer.
I do agree that's what it looks like... but if there's really a black tracer stripe then that's not what it is.

Would it work better to run the temp wire over the top of the valve cover and back along the intake?