81 XJ650 - Dimly Lit Oil Light

Noticed something when pulling into my garage today. My oil light was dimly lit, so dim that I didn’t even notice while riding around in the daylight.

The oil level itself seems okay. Nothing visible in the window when on the side stand, then quite full on the center stand. I’m going to check again once the bike is cooler, since reading when it’s ripping hot could make it seem falsely high.

Does this mean I have a bad connection in the electrical system somewhere? I took the low oil sensor to be a binary sort of deal: “It’s low” or “It’s not.” Is this correct?

 

Symptom update, I guess. The light is fully off when the key is turned to On, but the engine cutoff switch is off. When the engine cutoff switch is switched to Run, the light is dimly lit.

So, related to the in-gear sensor, perhaps? I don’t think my Maxim has a side stand sensor, so I don’t know why else it would have this behavior.

 

How does it look when pressing the start button - put it in gear and push start it should get bright

 

Nothing to do with the neutral switch.

The 12V positive side of the light is switched by the run switch so this makes sense.

The negative side of the light is provided by two places, the oil level switch and the starter button. It's unlikely that the light is "finding" some type of ground though the starter button or relay side of the harness so I would suspect it's finding some sort of ground through the oil level switch. You could try unplugging the oil switch from the harness (it's a pain to get to though) and see if the dim light goes away. IF it were me, I would make sure the light works when you drain the oil next time and call it a day if it does. I've learned to just make an oil check part of my pre-ride routine and not rely on lights.

 

Thank you for the suggestion. It still goes full brightness when the starter is cranking the motor, which I believe it should. I think I’ll proceed with the “check it during my next oil change” suggestion. I have checked and double checked the oil level, so I know it’s fine for now. Shouldn’t run into a problem unless I spring an oil leak mid-ride or something.