Reply To: [Tutorial] Gear position sensor fault – Neutral switch GV 250 Aquila EFI 2010
Hi, solved the problem with the neutral light not coming on and the FI light coming on.
It was the gear position sensor that was faulty, but I also measured it the wrong way. Here is how I think it should be:-
There are two wires coming from the sensor, one is blue and the other is brown. If you use a multimeter set to measure resistance you should see the following values when measuring from the BROWN wire to each contact on the gear position sensor (except neutral) 1st gear 99 ohms 2nd gear 295 ohms 3rd gear 505 ohms 4th gear 980 ohms 5th gear 1500 ohms. Measuring from the BLUE wire to the contact for neutral on the gear position sensor the value was 3 ohms, but I suspect this is just a direct contact to ground and my meter is not that accurate. On the broken sensor neutral and 5th gear was open circuit.
At the time I was trying to fix the problem, I could not find a second hand sensor or even a new one anywhere. So I bought a gear position sensor for a Suzuki GN250 from AliExpress for about £3 something. This sensor has seven wires on it, the black one is connected to the neutral contact so I removed the wire in the connector for 6th gear and put the black wire in its place the wire for 6th gear was just taped up out of the way as it is not needed. I wired up a plug to fit the socket that came with the sensor so that I have 5 resistors with values close to those mentioned earlier for each gear. The other end of the resistors are connected together and go to the brown wire. I have a 3 ohm resistor which is goes to the black wire in position 6 of the connector the the resistor is connected to the blue wire. This has been working fine for some time now and no oil leaks. I have attached a couple of pictures that might help if someone wants to try this themselves. You can see in the picture with the resistors that the one for neutral is separate from the others, this one is connected to the blue wire and all the other resistors are connected to the brown wire.
It should be noted that the flange of the sensor for the Suzuki is not as wide as the original, nor does it have the little brass inserts where the mounting bolts go, so you have to be careful when tightening the mounting bolts not to break the lugs where the bolts go through. It does fit and does seal ok even using the old “O” ring.
Hope this helps someone – at least to be able to measure the sensor to get an idea of the resistor values which might indicate whether the sensor is working or not.
Kind regards
Robert