50hp Nissan NOTHING WORKS

[GDFL]

Please help. I've spent hours trying to chase down the problem. I have a 2001 Nissan 50hp with PT&T. I have a known good battery giving 12v to the motor and 9v returning up through the wiring harness to the control box (I'm assuming 9v is normal for the controls). Nothing at all works. No choke, no click of the starter solenoid, no trim. The boat worked fine a few months ago before I got busy and couldn't use it. It is stored in my garage and has seen salt water a few times. The engine itself looks very good and the control box has no corrosion to speak of. I did notice that I have to unplug the red lead that goes to the gauges in order to get the 9v at the control box. With that wire plugged in, I'm only getting .89v. When I turn the key or push in for choke, the 9v goes to 0v. Please help. I'm dying to do some fishing.
Thanks,
Garrett

 

[TOHATSU GURU]

Re: 50hp Nissan NOTHING WORKS

Have you checked the fuse on th engine?

 

[GDFL]

Re: 50hp Nissan NOTHING WORKS

Yes, the 20 amp fuse is good.

 

[TOHATSU GURU]

Re: 50hp Nissan NOTHING WORKS

The most likely culprit is the connection betwwen the battery cables and the battery. Absent a multimeter you can check it by using jumper cables. If the battery cables turn out to be good then you will have to use a multimeter and troubleshoot the ignition wiring harness, ignition switch, etc,

 

[GDFL]

Re: 50hp Nissan NOTHING WORKS

I've tried two different batteries, one of which is almost new and fully charged. The harness from the motor to the control box gets 0 ohms on all wires when I check each one individually. Is it possible to get 12 volts at the motor (and 9v up to the control box) but still have a bad battery connection? Thanks for the help so far. This is incredibly frustrating.

 

[TOHATSU GURU]

Re: 50hp Nissan NOTHING WORKS

In theory no. But you have to start somewhere and eliminate every single electrical connection and electrical part as the "bad point" Sometimes it's the first thing you check...Sometimes its the last. Sometimes your better off letting someone else do it. Your service manual will have the values you need to check the electrical parts. Just start at the engine and work your way forward.

 

[GDFL]

Re: 50hp Nissan NOTHING WORKS

Just a bit of followup: The culprit was two wires inside the engine wiring harness (under the cowl) that had gotten water in the wires and completely corroded. I don't know how water got in there and I didn't see any signs of water from the outside of the tape or anywhere else under the cowl. It took a mechanic to figure it out. I went by yesterday to look at it and I should get it back today if the new harness comes in. Thanks for all the help. This one was frustrating.