Plug verification

[psn]

I'm chopping the harness, three plugs were left unlabeled and only thing I remember for sure is that they came from engine compartment.

1. Pass. side, looks like
it hasn't been connected
to anything in a while, heater/ac related?


2. I have no idea what this does,
or where it goes?


3. I'm pretty sure this came
from the brake proportioning valve.
What is it's purpose? I have vacuum brakes.

 

[psn]

Anyone? #2=knock sensor?

 

[big reazon]

On 3 even cars of mine that came factory with vacuum brakes had that plug.

 

[aminga]

If #2 has a green wire with a yellow stripe it's the High Speed Fan switch. Goes to a temp switch on the top of the manifold. The Knock sensor has the same plug but it's a blue wire.

 

[psn]

Knock sensor it is then. Is #1 heater or a/c related? If so, then it's no wonder I can't remember where it was connected, since I've dumped both of them.

 

[85begalttype]

3. I'm pretty sure this came
from the brake proportioning valve.
What is it's purpose? I have vacuum brakes.
View attachment 146789

My rear brake cylinder blew out and my brake light came on. That connection lets you know of loss of brake pressure.