4 replies to this topic

[KMP]

Hi all, we had a gearbox rebuild last year and I put the engine back together, i turned the engine with no plugs in to get the oil pump to pump the oil around the engine and got good oil pressure on the gauge.

I have great oil pressure on idle and revving but the orange light won’t go out, i have checked inside the t piece where the pressure gauge also connects and it’s clear.

Fitted a new Bosch oil pressure switch to see if that helped and nothing happened

Taken out the pressure spring/bullet thing and checked it moved freely in the engine and all ok there, how ever there was a bolt packing the spring to make the oil pressure better and that was how it has been for the last how ever many years and has always worked fine, taken the bolt out and still doesn’t go out.

When I take the wire off of the oil pressure sensor and put it on the engine to earth it, the orange light stays on and the red ignition light comes on too, is this normal?

The wiring loom is only a couple of years old and it worked previously.

Is there any tests I can do to see if the light will go out with either the switch or the wire? Could it be a bad engine earth? It seems to start fine though.

I can’t quite work out why the pressure gauge says it’s get plenty of pressure but the light won’t go out.

Thanks
Kris

[nicklouse]

increasing the pressure on the relief valve only raises the pressure that it opens to allow oil to pass it does not actually raise the oil pressure.

 

i would get a mechanical oil pressure gauge that you can screw directly into the block so you can check what the actual pressure is.

 

once you know what that is you can actually start fault fixing.

[Matpaul]

Could it be that the orange light is actually your alternator / generator warning light? Does the red light go out after startup? i.e. as soon as oil pressure picks up and then come back on again when oil pressure drops to near zero after switching off? 

[MrE812]

Sounds to me like the gauge might be correct and you have a short in your line to the oil pressure switch.

The switch operates by creating a circuit to earth/chassis ground when the pressure drops - so earthing to the engine will put the lamp ON.

If you remove the wire from the pressure switch the warning light should go out.

 

Not sure if all mini wiring throughout time is the same but the wire for the oil pressure switch on mine is White with a brown stripe.

The charge indicator from the alternator is probably a brown wire with a yellow stripe and is part of the alternator connector - pretty hard to get those mixed up.

 

If touching this to earth also lights up the charge warning/ignition lamp you may have another short here too.

I would carefully at the wiring loom to look for any obvious damage where it might have been crushed or sliced - perhaps when refitting the engine?

[KMP]

As it turns out, I’m and idiot! Thankyou for your replies, I had the ign/charge light and oil pressure lights in the wrong holders on the binnicle. So it was actually the charge light that wouldn’t go out, which then led me to the fact that I had wired the charge wires to the wrong side of the starter solonoid switch lol. Swapped it all over and it’s all good.

Thanks again

Kris