i was lookin over the truck today when i noticed these 2 plugs please tell me wat they are as i can not find anythi9ng in the haynes maunal.

this one has red/white red/ yellow and a black wire



this one look to have to black 2 wires commin off the backside of the plug i held it in my hand like this to get a better quality picture . i cant tell if its aftermarket or not or if the color has faded off the wires




p.s. thank god i got a whole new wiring harness comming soon hahahaha

 

This is for your 1977, Correct?

 

yea 77 f100 302

 

Top one not sure, bottom one looks like the jumper for the NSS on a stick shift.

 

Tell me the location these plugs you found in.

 

to the right of the brake master cylinder close to the main wiring harness commin out of the cab

 

Agreed, and the location jives. Mine's exactly the same.

 

The first one does sound like the NSS.

Second one, may be a solenoid used for vacuum control, which is a part of emissions. That is only found on the 302 engines. It ties into the ignition.

 

What truck with a stick shift (manual transmission) has a NSS (Neutral Safety Switch)?

None.

The NSS was only used with Automatic Transmissions.

1973/77: The NSS is mounted at the bottom of...and above the steering column inside the cab. The NSS's plug feeds off the dash wiring harness.

So...what's that plug doing under the hood if it's for a NSS?

The bottom plug is part of the engine gauge feed loom, prolly plugged into the coolant temperature sensor which was part of the IMCO emission control system.

The sensor has prolly been removed. This sensor threaded into the t/stat housing on some, into the intake manifold on others.

The coolant temperature sensor has nothing to do with the temp gauge on the dash.