Random wire

[tony81]

Can anybody tell me what this blue wire coming up behind my motor in between the firewall with a round rubber plug on it before it’s only one wire

 

[PrairieDrifter]

Yep it's one blue wire. One end plugs into a thingymajig. Then it plugs into a thing on the other end.

You're working on a 1942 ford right?

 

[DoubleDingo]

We need a pic of the wire, some info on the vehicle you're working on. I don't think any of us are capable of seeing what you see through your eyes. Take a pic, post it up, and provide info on what you're working on, then you'll get meaningful replies.

 

[Grit dog]

Assuming it’s your 78, my 77 that doesn’t have hacked up wiring does not have a single blue wire that I can see coming out of the firewall.
The only blue wires in the region are 2 of them that are parts of 2 plugs fling to the wiper/washer motor.
Rubber plug on a single wire sounds like a sensor. Oil pressure or temperature.

 

[ali_c20]

We need a pic of the wire, some info on the vehicle you're working on. I don't think any of us are capable of seeing what you see through your eyes. Take a pic, post it up, and provide info on what you're working on, then you'll get meaningful replies.

Welcome from Austria. Blue is a Ford wire, you can remove it.