Tohatsu M90a Oil Light/Pump

[bowtoot]

I have a Tohatsu M90A. It has been a champ for the years I haved owned it. It has started with the oil light and buzzer coming on. Accordiing to the owners manual, it would be low on oil. The tank is full. My question is this.

Is the light/buzzer alarm set off only by the oil level in the tank or is there another sensor that I am not seeing? Thanks.

 

[pvanv]

Re: Tohatsu M90a Oil Light/Pump

Take a look at your owner's manual. Page 62. If yours has been misplaced, there is a scanned copy available online at http://www.tohatsu.com/tech_info/manuals.html If the tank is full, you may have a defective oil level sensor.

 

[bowtoot]

Re: Tohatsu M90a Oil Light/Pump

So, the oil level sensor is the the only sensor that will make the buzzer and light sound off? Thanks.

 

[bowtoot]

Re: Tohatsu M90a Oil Light/Pump

I replaced the oil sensor with one from a donor motor. It is still buzzing with the light when placed in gear. I used my ohm meter to check the connection green to black(ground) with the wires off of the sensor(open). I am seeing continuity between the green wire and ground. Could it be a short, in the wiring or control box?

 

[pvanv]

Re: Tohatsu M90a Oil Light/Pump

I replaced the oil sensor with one from a donor motor. It is still buzzing with the light when placed in gear. I used my ohm meter to check the connection green to black(ground) with the wires off of the sensor(open). I am seeing continuity between the green wire and ground. Could it be a short, in the wiring or control box?

Your light-green wire should not be shorted to ground. The sensor connects the light-green to the black (black is ground) to trigger a low-oil indication. Odds are that the insulation has rubbed off the light-green wire somewhere -- somewhere that is ground. Since you mentioned that the alarm only comes on when in gear, check near the shift mechanism and linkages in the lower cowl.