VDO gauges problem

[KINGPRAWN]

Thanks... Every day a school day!! I'll give it a go .. Cheers

[KINGPRAWN]

Right ....digital meter with two probes together reads 0.00..
To wk terminal I get 0.00
But to G terminal .... Nothing!!!

[KINGPRAWN]

Right ....digital meter with two probes together reads 0.00..
To wk terminal I get 0.00
But to G terminal .... Nothing!!!

So will the sender hold the needle down and the pressure release it as it increases/decreases???

[icosahedron]

My oil pressure sender (not VDO, but a man or lady from the Far East hand-engraved it with VDO ) measures 9 ohm at 0 bar and 116 ohm at 5 bar. It does look as if yours is faulty as it is open circuit = infinitely high resistance. The lower the resistance the more the needle will drop as when you connected "g" to ground = 0 ohm.

[KINGPRAWN]

My oil pressure sender (not VDO, but a man or lady from the Far East hand-engraved it with VDO ) measures 9 ohm at 0 bar and 116 ohm at 5 bar. It does look as if yours is faulty as it is open circuit = infinitely high resistance. The lower the resistance the more the needle will drop as when you connected "g" to ground = 0 ohm.

Thanks so much for your help... So.. Is it the sender that restricts the travel of the needle? Not the sender that pushes the needle!! Only say this as said before the needle still goes off the scale with or without the sender....

[icosahedron]

Yes, the gauge works like the battery voltage gauge except that it is measuring the voltage between ground and the "g" terminal. The lower the resistance, the lower the voltage and needle reading. Yours is open circuit so the resistance is very high and therfore the full voltage is displayed on the gauge.

[KINGPRAWN]

You hero!!! Starting to loose my mind over this!!!

[KINGPRAWN]

Thanks all for the input and multimeter tuition. New sender arrived today and bingo... All is well. I seem to have had a duff sender with the gauges I bought... Sorted!