253 V8 carby selection

[Madmatt2006]

Probe the end you think is for the gauge and check for continuity to the sender wire

will do

['quipt4it]

.

[Madmatt2006]

I traced that wire from sender to that plug and no good. I'll be back with pictures soon about plug at back of motor.

[Madmatt2006]

I traced the blue wire from the sender to this plug.

blue wire plug to purple.jpg

untaped this wire behind the dash it's been sliced at some time

Dash wire.jpg

getting confused

Which colour wire should it be on the dash blue or purple

['quipt4it]

.

[Madmatt2006]

will check be back soon

[Madmatt2006]

well it connects from sender to dash

purple on dash.jpg

['quipt4it]

.

[Madmatt2006]

got another dash will hook up I'll go find it

[vlad01]

Have you looked at the gauge while the sender is disconnected and see if it drops to 0?
Have you measured the resistance of the sender? should be high resistance, ie. nearly open circuit when the engine is not running.

It might not even be a sender, could just be a pressure switch for an oil light in which case it will do exactly as you are seeing, fully pegged when no pressure as opposed to a sender which is high resistance when no pressure and low resistance when the pressure is high, basically the opposite to a simple oil pressure switch.