oil pressure and gen

[islander]

hey i wired in a new harness on my petrol and when i turn the key on one light comes on would that be the generator or oil. when i start only the same light stays illuminated. does oil pressure only light up when there is no pressure? can someone help clear this up for me thanks.

[pjjms]

Both lights should be on when the engine is not running and both should go out when the engine is running.

[islander]

Lights giving me a hard time. Wired light bulbs positive where one live wire comes from key switch and gives power from one bulb to the other bulb. Now the socket casing is ground where i have a wire from each socket casing, one going to oil pressure switch and the other to generator. However this setup does not work because the socket casing is grounded directly to the tractor, so clearly they are always illuminated.

i have to isolate the socket casings from the tractor and the only way i think i can do that is by putting rubber washers on the screws that hold the chrome dash plate on, the red and green bulb covers are plastic i think.

[PghBill]

Don't know about the Petrol, but I would assume that on the Petrol the Dexta and Super Dexta this part of the wiring would be similar. The ground went straight to the lamp.That's why there were two wires coming out of the socket.The socket was not connected in any way to the electrical circuit. Use a continuity tester to see if your socket is in fact grounded. Go between the ground wire coming out of your light and the socket case. You shouldn't have a circuit. Maybe your oil sending switch is bad or your wiring is grounded somewhere else

[islander]

new wiring and aftermarket lamps if i remember correctly they have a wire sodered on each lamp holder. anyway there is always a solution gonna pick at it some night this week

[Bensdexta]

As already said, bulb holders must be insulated.

See discussion here: http://www.fordsontractorpages.nl/phpbb ... ing#p24153

To test your oil pressure gauge wiring, simply remove the wire from the oil pressure switch and touch it to the block - oil light should illuminate.

[Jerry Coles]

Both the Oil pressure and Charge lamp wires are separate from ground (earth).
The Oil pressure switch earths the wire from the lamp which is fed by the ignition live feed. When the oil pressure rises the switch opens and disconnects the lamp so it goes out.
The Charge lamp is used to indicate the difference between the battery voltage when the ignition is live and the output from the generator. When the generator is not turning or not charging it has no voltage and so is close or at ground so the bulb lights as the ignition side is at battery voltage. When the generator voltage rises to charge the battery it is just above the battery voltage and so both sides of the bulb are at the same voltage and it goes out. You may see the bulb glow dimly on tickover where there is an output from the generator but it is slightly lower than the ignition so the bulb glows dimly. Increasing the revs should make the bulb go out. On an engine fitted with an alternator the same principal works but it is more efficient and the bulb should stay out.
So ensure that both wires at the bulb holder are not connected to ground (the case of the bulb holder) as pghbill says in his post.
Cheers
Jerry