Oil level gauge not working. replaced sender unit. shorting wire to earth: oil level gauge moves up

Good idea to check oil level first. Next, check that wire to oil pressure sender is still attached. Next, try hooking up know good mechnical gauge to insure you really have pressure. If all good, short wire to sender to ground--if gauge come up, replace sender.

Check that the wiring is still attached to the sender unit. If it is disconnect that wire from the sender and earth that wire to the engine.
Turn the ignition to the run position and watch to see if the gauge starts to rise. If it dose your problem is the sender unit itself and needs replacing.
If the gauge doesn't move you most likely have a fault in the gauge or wiring harness.

remove the wire connected to the temperature sender unit in the head . earth it out on the head. turn on the ignition and if the gauge goes to very hot then replace the sender unit . If it doesn't move then check out the wiring from the ignition switch ,fuse and wiring to the sender.. It may be the gauge but unlikely.

check coolant level at the radiator cap. disconnect the wire to the temperature sender unit . switch the ignition on and earth out the wire . If the gauge goes to full hot then replace the sender unit.

cars of this age normally did not have a ground wire . In stead they had screws that held in the sender unit act as an earth point. If you want to test the power wire to the sender just have some one look at the gauge while you touch the power wire to earth . The gauge should go to full immediately. Next to check the operation of the sender itself remove the unit from the tank and attach an earth wire to the unit and to a good earth point and physically move the float arm and watch the response on the gauge. If you have a dead section then replace the sender unit.

Check oil level.Check oil pressure with a mechanical gauge to ensure oil pump is working. Do not run the engine for any period longer than is necessary to do this test. If you have oil pressure then the fault will probably be in the oil pressure sender unit . Replace the unit after checking that the lead is not earthing out before the sender unit

Try this:
Tools Needed:
Multimeter, Screwdrivers sockets as required, knowledge on how to use multimeters.
1. Remove wires (wire) at tank sender unit. 2. Turn on ignition and test wires for:
a: voltage at positive wire b: good earth to grown (Using ohm setting on multi meter)
If two is ok..... go on to 3 .... if no power or earth issue.... trace fault in wiring and then reconnect and test.
3. Remove tank sender unit. 4. Reconnect wires and move the float level up and down ... you should see the gauge moving (it happens slowly so be patient ... try 1/4 ...1/2...3/4 ... and right up to the top (Full) and see if the gauge responds.
5. if the gauge does not respond or is erratic... then you will need to test the Rheostat on the sender..... 6. if you rheostat gives good solid readings (goes from high resistance to low resistance as you move the float through its range.... then go to 7.
7. you will now need to check the gauge in the dash cluster .... check the cable is connected and if so ... you will need to remove the gauge cluster and take it to a gauge specialist and or get a replacement to try from the dismantler.
Hope this helps ... cheers Westy

Sound like a posible bad oil pressure sending unit . It is normal for pressure to be above normal just after starting . At a cold idle , the oil viscosity is higher than it would be if it were warm . If the guage is reading really high for longer than normal ( after 1 minute of cold idle ) then I suggest having the sending unit checked .A sevice center can check the sending unit on or off the vehicle as well as checking pressure with an actual guage for more accurate readings .

First things first obviously you want to check the oil level.

Assuming that the level is good, and the oil isn't sludge, then we can move on.

If the engine runs smoothly we will have to see it it is a faulty gauge, or a faulty sender. If the engine knocks, and rattles, then it may be a serious problem, which may need to be brought in for professional help.

To test the sender and gauge first turn your ignition to the run posistion with the vehicle not running.
Then look at you oil pressure gauge. If it reads 0 you will then want to locate the oil pressure sender and unplug the unit. If the gauge goes up then your gauge is working properly, and you sender has failed. Replace the sender and you should be golden.

unplug the wire from the fuel tank sender unit and earth that wire to the chassis. switch the ignition to the on position,not crank, and see if the dash gauge starts to move to the on position, if it does the problem is at the tank sender unit, assuming that the wire to the gauge is not damaged. sometimes just pulling that wire off can re-establish a decent contact when you reinstal it.also the tank sender unit should have a good earth.