1998 VRO Electronics

[Blakek25]

The tachometer no longer works for my 1998 Johnson outboard. After some troubleshooting, it looks like the issue is in the VRO electronics. The tachometer works as it should when the VRO plug is disconnected. When the VRO plug is plugged in, the DVA reading on the gray signal wire leading to the tachometer almost disappears, like it is grounded out. I was wondering if it would be acceptable to just cut the gray signal wire leading to the VRO pump, or if this would have any negative affects such as disabling the VRO alarm system, or turning the alarm on continuously? Another option would obviously be to buy a new part, but I was not able to find just the electronics for the VRO, without buying an entire new part. Does anyone know if it is possible to purchase just the VRO electronics? Right now it looks like the best option would be to buy a used VRO.

 

[flyingscott]

What motor do you have? Check the diode and I believe the purple wire connects to the Vro not the gray. The tach not working is usually a rectifier issue not the VRO. Find the wiring diagram for your motor.

 

[Blakek25]

Sorry, I have a 1998 Johnson 225 model number J225stlecs. There are 4 wires going to the VRO, a black, gray, purple, and tan. I have attached a picture of the wiring diagram. The rectifier/regulator was just replaced because the motor stopped charging. I thought this would also fix the tach issue, but when it still didn't work, i decided to check the rest of the system. The manual mentioned the possibility of the VRO being an issue as well.

 

[flyingscott]

Look at the diode I.believe you have one. The electronic part is available for the pump but i do not know the part #. look up the.posts.from cfauvel he had it posted.

 

[Chris1956]

I would think you want to verify the issue is with the OMS pump electronics, before you replace it.

1 Check the wiring harness near the OMS pump for melted wires or bare wires.

2 With the motor off and the system check tach, VR and OMS wiring unplugged verify grey wire is open. Now plug in the OMS and see if the grey wire indeed shorts to ground. If so, test the OMS pump grey wire for grounding.

I am not sure why the OMS pump would need the grey and purple wires, but if they went to the trouble of connecting them to the OMS, their is likely a reason.

 

[Blakek25]

Thanks for the Info!
flyingscott, I am not sure what you mean by diode. Where would this be located?

 

[Faztbullet]

I am not sure why the OMS pump would need the grey and purple wires

Purple to power the electronics, grey for IC chip(counts pulses)