Morris Minor Owners Club

Hello folks, I noticed today that my oil warning light does not come on when I turn the ignition on. However, the ignition light does come on (and goes out when the engine starts up). Everything else works OK. I'm wondering if the oil pressure switch is faulty - I thought I would remove the wire from the switch and then earth it, thinking if the warning light then comes on, the switch is faulty. If not, could it just be the bulb? Any other thoughts? I'm thinking its got to be simple but haven't had time to check yet.

Could be the bulb, could be a wiring issue, could be the bulb holder has dropped out of the speedo, circuit is very simple, live to one side of the bulb the other side of bulb goes to the switch and is earthed to the engine when the switch closes. So yes first simple check is to earth the switch wire and see if the bulb comes on, if it doesn't take one of the gloveboxes out and test the bulb.

This happened to me and a replacement switch cured it. But yes do what kevin says first.

Hi chaps. I earthed the feed wire to the switch and the warning light came on. So it must be the switch. Presumably the swap is easy - I mean, I don't need to drain the oil first? I don't want oil squirting out over my newly cleaned and painted engine bay floor!

No need to drain the oil. Just unscrew the switch and pop a replacement in, making sure it is reasonably tight.

myoldjalopy wrote: ↑Thu Jun 02, 2022 11:50 am Hi chaps. I earthed the feed wire to the switch and the warning light came on. So it must be the switch. Presumably the swap is easy - I mean, I don't need to drain the oil first? I don't want oil squirting out over my newly cleaned and painted engine bay floor!

Oil level is at dipstick level - below the crankshaft.

It’s not likely to squirt as there will be no pressure - apart from few cm of head in the oil gallery.

Some oil will dribble out.

Changing it when the engine is cold will slow the dribbles (thicker oil).

myoldjalopy wrote: ↑Thu Jun 02, 2022 11:50 am Hi chaps. I earthed the feed wire to the switch and the warning light came on. So it must be the switch. Presumably the swap is easy - I mean, I don't need to drain the oil first? I don't want oil squirting out over my newly cleaned and painted engine bay floor!

Not unless you intend changing it with the engine running; that is after all what the switch does, detecting oil pressing on it when the engine is running...
Just put an old rag or bit of paper towel under it for good measure.

oliver90owner wrote: ↑Thu Jun 02, 2022 3:55 pm Oil level is at dipstick level - below the crankshaft.

Of course it is - silly me! I didn't think it would be a problem but - best to be safe than sorry!

Job done - it looked a bit awkward to get an ordinary spanner on there so I found a perfectly fitting old box spanner. Sorted in less than five minutes, a nice easy fix - we like them!