1986 Evinrude 225 v6 only 5 volts at harness plug

[cbar]

I have a 1986 evinrude 225 v6. it will crank and has spark if i bypass wiring harness plug I can only get 5 volts on the engine side of the plug when in plug it in the choke horn alarm work but won't crank with key. also when i put a spark tester on and kill switch has lanyard in the spark gage is strong. when i pull lanyard it still has a light spark. I have used meter on everything and I am frustrated beyond belief. fuse is good but NO wires get 12 volts the the engine side of plug when hooked up.

thank you

 

[Crosbyman]

I can only get 5 volts on the engine side of the plug when in plug it in.
the choke, horn alarm work but won't crank with key.
Fuse is good but NO wires get 12 volts the the engine side of plug when hooked up.

Q1- do you have 12v on the selenoid main post ? you should.... if not clean all main 12v and ground connection battery side and engine side

the fact it won't crank with key indicates the selenoid is not receiving the key signal to energized the selenoid. Have you cleaned all the pin contact areas in the plug halves. ?

start with a simple test.... have a friend hold the key on START and wiggle
all accessible wiring, plug, shift handle(neutral switch test) etc.... turn the engine side to side ... if you get a reaction (engine cranks) you likely have a bad connection or broken wire

 

[cbar]

I can only get 5 volts on the engine side of the plug when in plug it in.
the choke, horn alarm work but won't crank with key.
Fuse is good but NO wires get 12 volts the the engine side of plug when hooked up.

Q1- do you have 12v on the selenoid main post ? you should.... if not clean all main 12v and ground connection battery side and engine side

the fact it won't crank with key indicates the selenoid is not receiving the key signal to energized the selenoid. Have you cleaned all the pin contact areas in the plug halves. ?

start with a simple test.... have a friend hold the key on START and wiggle
all accessible wiring, plug, shift handle(neutral switch test) etc.... turn the engine side to side ... if you get a reaction (engine cranks) you likely have a bad connection or broken wire

Thank you for your reply.
The frustrating part is we can not get any pin or wire at the engine side of the plug to ha e 12 volts one gets 5 volts but that’s it. Have 12 at fuse. Also when we jump the power around the plug and do a spark test we have good spark but when we put in gear it still cranks and if we remove kill lanyard it still has a slight spark not as strong as normal but still slightly. It seems easy to say it’s the plug but why when jumping power do we have the other issues.

 

[Crosbyman]

what exactly is it you do to JUMP THE POWER AROUND THE PLUG ??
are you " bridging wire to wire " ??? if so the contacts need to be cleaned ...did you ?

when we put in gear it still cranks...? are you saying the starter keeps spinning or trying to spin the engine while in forward gear ??? if so the selenoid is sticky or the switch is bad or... the control wire to the selenoid is at constant 12 v due to a short across a 12v source

you seem to have to many symptoms fix one at a time ! did you inspect the wiring & connections , wiggletest done ....initial symptom was NO CRANK WITH THE KEY but now it cranks to much ??

 

[Crosbyman]

see diagram of a " similar" 1985 engine" it may help track down problem areas as you track down the missing 12 volts

 

[cbar]

what exactly is it you do to JUMP THE POWER AROUND THE PLUG ??
are you " bridging wire to wire " ??? if so the contacts need to be cleaned ...did you ?

when we put in gear it still cranks...? are you saying the starter keeps spinning or trying to spin the engine while in forward gear ??? if so the selenoid is sticky or the switch is bad or... the control wire to the selenoid is at constant 12 v due to a short across a 12v source

you seem to have to many symptoms fix one at a time ! did you inspect the wiring & connections , wiggletest done ....initial symptom was NO CRANK WITH THE KEY but now it cranks to much ??

Yes a wire to wire bridge. When motor is out in gear and have wire to wire bridge in place it still cranks. Yes have cleaned all terminals and traced wires with diagram. Choke engages warning horn works (albeit not normal volume ) yes from battery to solenoid 12 volts. Only at engine side of plug doesn’t have 12 volts has 5 on pin. 12 volts at fuse link.
We bought a boat (for the boat bull had this motor) the boat has been run in salt water and has sat for 3-4 years. The motor will run however we at this point we want to run it on a hose for awhile but ha e no way to shut it off without key / kill switch working (well any good way LOL ) thank you for reply

 

[cbar]

see diagram of a " similar" 1985 engine" it may help track down problem areas as you track down the missing 12 volts

Thank you for reply we have the diagrams (from max rules I believe and few other google sesrches) i feel we have a plug issue. I guess a question. Would be should we bypass plug and by pass kill switch? The multiple symptoms is what is frustrating why is there a slight amount of spark when kill switch is engaged. If we only had the volt issue fine but when we bridge passed plug then the kill switch seems faulty and why 5 volts. Is that leading to a bad ground in plug which also is causing kill switch issue ? I believe kill switch grounds out motor so the. No fire

 

[racerone]

Do a full inspection of the wiring cable from control box to motor plug in.------Control box is only to be used for motor functions.-----No instrument / radio / fish finder is to be operated from motor control box.

 

[Crosbyman]

reading 5 volts along a wire.... indicates that the source voltage (12v) has dropped in proportion to the resistive load ..... as in Ohms law.

wherever your read 5 volts "across" something means the 12v is being shared along a resistive path between a solid 12 v at a source down the road to 0 v at the ground referrence point. If you open that juncture point where you measure 5v .... voltage would jump up to 12v being now... the highest resistive point in the path (open air)

I am afraid you will need to track the issue down in sections but... if jumpering across the connector wire for wire solves problems I still suspect the connector inner contacts or harness.

that is how they fix bad hearth circulation... by doing bypasses

 

[cbar]

reading 5 volts along a wire.... indicates that the source voltage (12v) has dropped in proportion to the resistive load ..... as in Ohms law.

wherever your read 5 volts "across" something means the 12v is being shared along a resistive path between a solid 12 v at a source down the road to 0 v at the ground referrence point. If you open that juncture point where you measure 5v .... voltage would jump up to 12v being now... the highest resistive point in the path (open air)

I am afraid you will need to track the issue down in sections but... if jumpering across the connector wire for wire solves problems I still suspect the connector inner contacts or harness.

that is how they fix bad hearth circulation... by doing bypasses

Yes I understand and very nice and helpful.

 

[cbar]

UPDATE
So we first went to “easier” LOL issue the kill switch. It is bad we manually grounded it out and now it has NO spark (instead of slight) when grounded and normal when not.
2nd we as suggested by Crosbyman ( and thank you again) we started at the power connection on motor and found a spot after wires came out of trim box (maybe a different name but has trim wires and others before plug on engine side) and found where 2 wires had a factory connection to one hot wire. After conducting multiple test the wire was bad and we redid the connection and temporarily added a piece of newer wire to test. This gave us power to the key with no jump passed the plug. Motor cranked from key. We unhooked it tested again to ensure results the problem was back so we hooked up the fix and motor again cranked as designed then quickly stopped. So did we for evening LOL. Thank you to all. We are going to just order new harness for motor side of plug and install.

 

[Crosbyman]

I am not to certain I understand precisely ... what you found but if you found the problem great.

before you spend $$$ did you try polishing all the surfaces of male/female contacts of the connector. It may be all it needs

thanks for the feedback

 

[cbar]

I am not to certain I understand precisely ... what you found but if you found the problem great.

before you spend $$$ did you try polishing all the surfaces of male/female contacts of the connector. It may be all it needs

thanks for the feedback

LOL sorry in understand your difficultly in understanding my prior post. Basically the wiring that goes from the “engine “ side of plug to motor is wire out and frail. We did clean with electrical cleaner and old emery board style on the plugs. The issues seem to be wire corrosion inside the wire from salt water use and sitting. So buying a new partial harness should be best way. But we are verifying Initial testing results to make sure. Again thanks for your comments and perspective. We have a lot of NON outboard experience with race boats and high end motors but the lack of real outboard knowledge causes self doubt and frustration. The same due diligence process as you basically suggested always seems to solve problems!! Thanks!! Will update when finalized.