Wonky electrical problem

Beatyouthere

Seaman Apprentice
Joined
Aug 13, 2024
Messages
35
Hello everyone I have a 1987 Johnson 225 V6 the VRO is deleted I tested the beige wire coming from the temperature sending units and everything checks out my problem is my warning horn for overheat is on and won't shut off it comes on before I ever started the motor is not at full sound it's a little weird to try to describe it but when I ground the beige wire it comes on full blast like it should i have gone through the harness and can't find anything wrong I believe I have a dead short somewhere but I am unable to find it I've tested everything I know to check and when it came to the starter solenoid I find that I have ground on both the black wire and the red and yellow wire also with the starter disconnected from the solenoid I have ground at both posts on the starter the obvious ground wire and
the starter wire that comes from the solenoid I have not checked to see what happens when I turn the key any information from someone with more experience would be highly appreciated
Thank you in advance
Beat you there
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,439
if you disconnected the VRO and both heat sensors does the alarm still sound or weeeez ?

have you compared the resistance to grd on both sending units (engine OFF and engine running at norm temp. ?

see diag on a 175hp.

Solenoid yellow-red is START from key ..nothing to do with the alarm. chase one problem at a time

the 1988 225hp wire drawing is a bit more tricky andmay apply to 1987 225 hps
https://maxrules.com/graphics/omc/wiring/1988_89_200_225.jpg
 
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Beatyouthere

Seaman Apprentice
Joined
Aug 13, 2024
Messages
35
if you disconnected the VRO and both heat sensors does the alarm still sound or weeeez ?

have you compared the resistance to grd on both sending units (engine OFF and engine running at norm temp. ?

see diag on a 175hp.

Solenoid yellow-red is START from key ..nothing to do with the alarm. chase one problem at a time

the 1988 225hp wire drawing is a bit more tricky andmay apply to 1987 225 hps
https://maxrules.com/graphics/omc/wiring/1988_89_200_225.jpg
Thank you I will check the heat sensors I have the OMC manual with the electrical drawings that's what was making me wonder why there were grounds on the starter and solenoid the yellow and red wire and the red wire at the starter but that is normal I have found out
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,439
heat sensors are like thermostats that react to heat
a varying resistance results and triggers the alarm ...

one or the other may be faulty and not working within heat range specs causing the alrm. try disconnecting one then the other see what happens.

if you still get an alarm with sensors disconnected work back from the alarm buzzer ......

disconnect at the buzzer to confirm it does shut off and not buzz on it's own ! ...reconnect the wire and work backwards to the engine buy tracing the culprit wire . inspect for chaffing, crossed wires etc... till the buzzer stops
 

Beatyouthere

Seaman Apprentice
Joined
Aug 13, 2024
Messages
35
heat sensors are like thermostats that react to heat
a varying resistance results and triggers the alarm ...

one or the other may be faulty and not working within heat range specs causing the alrm. try disconnecting one then the other see what happens.

if you still get an alarm with sensors disconnected work back from the alarm buzzer ......

disconnect at the buzzer to confirm it does shut off and not buzz on it's own ! ...reconnect the wire and work backwards to the engine buy tracing the culprit wire . inspect for chaffing, crossed wires etc... till the buzzer stops
Thank you I found it that's exactly what was wrong the beige wire was shorting out inside the red plug
 
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