Hello, all. I have a 2008 Ninja 250 with about 2k miles on it. I started it up the other day, and the oil light didn't go out. I was worried until I noticed that the temperature warning light didn't go out either. With both lights on, I figure it's an electrical gremlin and not an actual oil pressure failure. Anyone have a clue where I should start troubleshooting?

 

I'm sure I dont have to say this, but I will anyway, Start by checking your oil and coolant levels
After confirming that you have no problems with the fluids it has to be a fault in the sensor or in the display. I havent dealt with the electronics on the newer bikes, but check the wiring diagram and parts fiche to see where the sensors are and how they are routed, then check all connections. If the connections are good, your FSM should tell you how to test the sensors, and replace any bad ones. I doubt there is a problem in the display or that two sensors died at the same time, so probably wiring but like I said I never messed with it. Is it still under warranty?

 

Yep, the first thing I checked was the oil level. Unfortunately it isn't under warranty any more. I guess there's nothing for it but to start tracing wires!

 

Not sure on the 08, but there are a couple of other possibilities to look at. Oil viscosity? Pressure switch (mentioned already), oil screen clogged, relief valve stuck open, o-ring at the oil pipe in the crankcase damaged, oil pump damaged.

I would change the oil, the filter, clean the relief at the same time. Then go from there. Do not forget that the Mounting bolt for your filter has a bypass valve built into it as well. That may be gummed up. Good luck on the fix.

edit: but this may not explain the temp light issue, hmm

 

I determined today that it's normal for the oil and temp lights to come on at the same time when the bike starts. The temp light goes out when the oil light goes out, normally. If there's no oil pressure at start up, neither goes out.

I used a multi tester to verify the switch was not breaking the circuit as it should when pressure is applied. Thought surely it must be a bad switch with such low mileage. I took the switch out and started the bike, and no oil came out the hole, though.

 

Oil and temperature light, especially with a cold engine, is certainly an electrical gremlin and not sensor related.

Look for a loose connector, or water in a circuit. Try spraying the dash and the wiring into it with WD40 and leaving it overnight. Worst case might be a faulty dash.

If the temperature light is supposed to come on with the ignition and go off when the motor starts, check that no relays have been dislodged. The lack of oil pressure won't keep the temperature light on - until it causes the motor to overheat. The light should go out when the starter relay is released. Look at the wiring to the starter relay and the starter push button - can't remember which end supplies the power. Sort out the issue with the temperature light and I'd guess that you'll have sorted the oil light as well.

You can easily check the oil level. I assume that you've already done that.

Rob

 

The two switches are definitely connected. From the service manual:

"The water temperature warning light goes on when the
ignition switch is turned on and goes off soon after the engine
starts running (oil pressure switch off) to ensure that
its circuit functions properly."

The oil pressure switch is continuous to ground when there's no pressure. The circuit breaks when there's pressure, and it turns off both lights. After disconnecting the oil pressure switch, the temp light no longer comes on when I start the bike.

 

Ah ha! Problem solved. A friend of mine suggested shooting some compressed air down into the socket where the oil pressure switch plugs in. That did the trick. Apparently the previous owner of this bike left it sitting too long without running, and a clog developed.

Next steps: run it up to temperature and change the oil and filter, then put a few miles on it and change them again.

 

hmm, congrats on the fix. I had to look over my schematic. Up to an 04 model to try and understand the logic of why these safeties are not specific to the issue that is causing the problem. yes, they both share the same ground of course. But the water sensor is on a different circuit from what I see. However, both of these lights go into the same molex/connector that goes into the harness. Could you also have a bad connection on that harness which would cause both lights to illuminate? Just curious is all but congrats again on the fix.

 

Here's the 2008 circuit for comparison if you're curious: