951Gary

Been getting the oil level light. Pulled the connector off and measured resistance from sensor pin to ground, found about 26 Ohms with the oil full. Grounded the wire and the light stays off when start the car. Played around a bit with resistors between the sensor wire and ground and found that any value above 22 Ohms set the oil level light aglow.

Pulled my sensor to see what's up, expecting to find sticking float, bad contacts etc. Measure resistance on bench with float in up position, now < 2 Ohms. Cannot in fact find any position of float that gives 26 Ohms, or in fact anything other and open or < 2 Ohms, just like one would expect.

What I did not see was anything that I understood to be contacts, or a switch. I'm mystified as to how this works at all. I'd like to understand it to give me more confidence that putting back is not just a waste of time. The float appears to have a metal sleeve that rides up and down on the shaft, but the shaft is fully insulated. I pulled the float off and proximity of the top of the float to the shaft (coming in sideways) closes the "switch". I don't notice any magnetism from the float, and a chunk of iron in proximity to the shaft does nothing.

Anyone out there know what the switch part of the sensor is?

thanks
Gary

951Gary

bump...

xsboost90

not sure exactly how it works but if its low the float will set the light off....i have another one here if you want to try it.

951Gary

xs,
thanks for the offer. Since it works on the bench, I'm thinking of tossing it back in tonight. If it fails again, I'll take you up on that offer.

thanks
Gary

951Gary

I suspected that it had a magnetic reed switch and I was correct. When I looked for magetism the first time, I just didn't check carefully enough. So inside the post is a magnetically actuated reed switch - the contacts are on ferromagnetic "reeds". The float has a ring-shaped magnet inside it. It's fairly weak, as it takes very little to move the reeds. I happened to have have some ceramic ring magnets laying around and sure enough, they will close the switch from more than an inch away.

so there you go
Gary

jblobner

So I know this thread is old, but did you find a solution? I am having the same issue.

951Gary

In my case, the sensor appeared to work on the bench, so I put it back in the car. The next time that the level light lit up, I threw in the towel and simply jumped the sensor wire to ground, which is what the sensor is supposed to do when the level is sufficient. That seemed to work, but I would still get the level light on occasion, so the most likely cause of my issue was somewhere in the wiring.

So you could short your sensor lead to ground, and if the light stays on, the sensor is not the problem.
Gary

jblobner

I really appreciate the help.

I grounded the lead wire and the light is off. I am assuming the light out condition means the sensor is most likely faulty.

lamrith

I found on our car it like the oil to be right at the full mark or even above it. I was not a fan of the light at 1st, but given it is an old car, has a small oil leak, etc. it is nice to have given the car is being used by a new driver. Great reminder to check his fluids!

jblobner

I'm not a big fan of the light either, but I like things to work. I think I'm going to buy a new sensor. I'll update after it's installed.

aussie944cab

Check that the earth ring terminal is connected at switch and is grounded at the other end

jblobner

aussie944cab. Thank you very much for the suggestion. Where are the earth ring terminal and the switch located?

aussie944cab

The sender is located on the sump, just below the exhaust, there should be a "push on" connector and a brown wire with a ring terminal, this eaths out the sender by being on one of the 3 bolts, where it earths to the body, I don't know, I'll have a look at the wiring diagram when I get a chance, Just looked, it's grounded on the clutch bell housing, behind and to the right of the head

951Gary

You might consider using the car for awhile to make sure that the light stays out and is not a wiring issue. Mine was intermittent after I jumped the wires together, implying that the sensor was not the only issue. But for awhile the light stayed out. Those sensors are kinda $$$
Gary

Dan Martinic