Looking for wiring diagram for black box located on port side of engine by head.

a69nova

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May 12, 2011
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Believe this box is the timing advance. I discovered that the tan wire is disconnected, and it should go to one of two screws at a terminal block located above the alarm module box closer to the top of the starboard side head. another problem I found is that there is another small black box located near the topof the motor between the heads which has red and yellow wires running to a terminal block. Not sure if this is a voltage regulator or rectifier of some sort. Anyway it looks like it burnt up or fried at some point. The engine is an 88 mariner v150 serial# b279500 Any helpwould be great
 

Faztbullet

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Re: Looking for wiring diagram for black box located on port side of engine by head.

The module with the tan wire is the oil warning module and it sounds like oil injection has been bypassed. A advance module would would only have a red/wht/blk wire. The red/yellow wire at attached to a voltage regulator which has failed($200). This can be bypassed also...
 

a69nova

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Re: Looking for wiring diagram for black box located on port side of engine by head.

Thanks for the reply. Don't think the oil injection is bypassed because I keep filling my main oil tank when it gets low. Any idea where that tan wire coming from black box on port side of motor should go to? There are 2 screws where the tan wire is hanging, believe it goes to one of these.
 

a69nova

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Re: Looking for wiring diagram for black box located on port side of engine by head.

Faztbullet can you describe how to bypass that voltage regulator? Thanks again
 

j_martin

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Re: Looking for wiring diagram for black box located on port side of engine by head.

You aren't getting the power on test beeps because the oil alert module is disconnected. On the starboard side of the engine, above the switchbox mounting, there's a terminal strip. One screw is power to the oil alert. The other screw has that tan wire off the oil alert, a tan wire going into the harness, and another wire of any color going to the overtemp switch. With the ignition key on, if you ground that screw, the alarm should sound.

I'll bet if you hook up the oil alert module, it will sound off. Someone disconnected it because there is a fault in the system. The diagnostic routine is in the mercury service manual.

You bypass the voltage regulator by disconnecting it and filing it in the round file. If you maintain your battery (keep the water up) it is not needed.

hope it helps
John
 

a69nova

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Re: Looking for wiring diagram for black box located on port side of engine by head.

thanks for the reply. What do you do with the yellow and red wires that now need a home? What did you mean about filing it down in the round file? You mean trash it...lol thanks again. Also I hooked up that loose tan output wire from the oil warning module, and your right te alarm went off when the key was turned to the on position. I tried disconnecting the oil cap blue wire and the blue wire that comes from th oil sensor by the pump,its still sounding the alarm. I think I need to replace the module?
 

j_martin

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Re: Looking for wiring diagram for black box located on port side of engine by head.

round file = chit can.

The square box on top of the motor is the regulator. Just remove it and chit can it.

The rectifier on the side may or may not be OK. Look up the FAQ on this site to test it with an ohmmeter. If you want to replace it with something reliable, look up rectifier, modify the search with my name, and dine freely.

If the alarm goes off immediately on key on, not just 4 or 5 test beeps, then the oil alert module is bad. Any other fault requires the engine to be running for an output from the module. Any oil alert from a carbureted or EFI v6 will work with a little creative clipping and splicing. You can test the tank sensor with an ohmmeter, and the rotation sensor with a voltmeter if the module still supplies 12 V to it. No matter what, it's worth it anyway because it's obviously oiling OK.

It's a known fact that the module is sometimes poorly potted, causing them to fail from moisture.

Running without the alarm system running is like running an automotive engine without the oil gauge or idiot light connected. When oiling fails your first indication is a seized engine, or parts flying at you.

hope it helps
John
 

a69nova

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Re: Looking for wiring diagram for black box located on port side of engine by head.

J Martin thanks again for th info. I know understand the chit can part,but I feel alittle un easy about leaving the red n yellow wires just tucked away. Should i wrap them in elect tape, or trace back and snip altogether?
 
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