97 OMC wiring harness connections

[jim dozier]

I am rigging my 1997 Evinrude 115 on my boat to replace my 87 Suzuki DT85. After I had unplugged and removed the Suzuki and laid in the wiring harness for the OMC I realized that I don't know where to tap into the harness for power to the fuel gage and temp gauges. I want the gages to power up only when the ignition is on. The Suzuki had a power wire coming out of the the ignition switch in the control box but the OMC box just has the 6 pin connector for the engine and the 3 pin connector for the tilt&trim coming out. There is an unused connector (the previous owner installed a trailer connector) that I thought was for a tilt and trim indicator gage but I don't recall the color of the wires. Anybody know the best way to power up my gauges?<br /><br />Also it seems that the tilt and trim works even with the key off. The engine had been connected to the battery for several hours when I was standing around scratching my but and the motor suddenly went up by itself . I think there is a short in the control handle because I had to jiggle the wires in order to get it to come down . Now I'm afraid to leave the battery switch on.

 

[jim dozier]

Re: 97 OMC wiring harness connections

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[seahorse5]

Re: 97 OMC wiring harness connections

The boat harness wiring from the motor to the control box has the 6 pin connection for the control box, an 8 pin connector for the System Check tach or gauge with the 4 warning lites, and a 3 pin connection for the trim. Also there are 3 wires taped off, purple +12V, black (ground) and grey (tach wire used for aftermarket tachs). Use the spare purple and black for your dash guage power.<br />Trim is supposed to work with the key off, but like you thought, you have a shorted switch or wires.

 

[jim dozier]

Re: 97 OMC wiring harness connections

Thanks Seahorse. I was looking at the "taped" wires you described last nite. These appear to be the ones I said the previous owner had a "trailer connector" on. The kind that has a flat 4 pronged rubber connector with one open and 3 covered. It has a black wire which I confirmed is a ground, a purple wire which you said was +12v but appeared on mine to be another ground and a tan wire with a stripe that didn't have power or ground. The 4th wasn't connected. I was doing this in the dark with minimal lighting before I read your post so I am going to retest it tonite. I'll just have to trace these wires to see where they go. It sounds like I'll be able to use them. I have the Systems check tach gage so I won't need the tan wire for an aftermarket gage and will probably disconnect it an use it for a temp sender. I'll use the purple for gage power. Thanks again for clarification

 

[seahorse5]

Re: 97 OMC wiring harness connections

Oops, forgot about the second "taped off" 3 wire set with the tan stripe wire, that is for your trim guage " S " terminal.<br /><br />purple is +12V only when the key is ON.<br /><br />There should be another "taped off " set of 3 wires which are what I first described, and used for an aftermarket tach. Many times they are folded back against the harness and taped over by the installer.

 

[jim dozier]

Re: 97 OMC wiring harness connections

I retested the purple wire in the tilt trim group and its 12v+ so I used it for the gages. I don't have a trim indicator. I don't know where the other group of wires is. I ran a separate wire for the temp sending unit.<br /><br />I'm still a little leary of the ghost tilt&trim activation. It happened again when I pushed in the primer on the key so I dismantled the control box and checked the key switch and control handle for crimped wiring. Everything looked OK so I don't know whats up. I'll take another look at the wiring diagram tonight and see what else I can check. I guess the short could be on the engine side as well. Everything is wired up and ready to go. I would be less concerned about the ghost activation except that the motor hits my bimini top on the way up if I don't lift the bimini and it put a dent in it the first time it went up unannounced

 

[jim dozier]

Re: 97 OMC wiring harness connections

One other important point/question. I noticed when I hooked up the purple wire for my gages that it had 12.75v+ with the key on as expected but it also had 0.5v+ with the key off. Is this normal to have that much voltage with the key switch off? Or is this part of my problem with the ghost activation of the tilt trim motor? Electrical is not my forte. I understand the principles but I'm short on experience. I would think that a 1/2 volt to the purple wire when the boat is sitting in the driveway would drain my battery sooner than normal. Would the problem most likely be the ignition switch or a short some where else. The problem is I have never really checked "normal" wiring so I don't know whats OK and whats not OK.

 

[dolluper]

Re: 97 OMC wiring harness connections

Should have nothing at the switch when it's off, the reason for having a switch ,must be leaking across term's

 

[jim dozier]

Re: 97 OMC wiring harness connections

OK the good news is I found the problem with the ghost trim activation. Stray wire strands at the solder terminals of the control switch on the control box. Needed a magnifying glass to find that one.<br /><br />The bad news is I am still wondering about the 0.5+ to 0.6v+ on my purple power wire when the switch is off. Its still there when I unplug the switch so its not the switch itself thats the problem. Gonna do some further tracing back in the harness towards the motor to try and exclude things and narrow the problem down.

 

[jim dozier]

Re: 97 OMC wiring harness connections

I have traced the 0.5v+ back to the engine. If I break the 6 pin connector from the boat harness to the engine (which contains the purple wire) but keep the red battery wire in it connected I still get 0.5v+ at the engine side of the purple wire with the ignition switch completely disconnected. This would lead me to believe the the source is in the rectifier/regulator assembly because thats the only thing left I haven't checked. The only other thing that the purple wire goes to is the VRO and I checked the connection there and the 0.5v+ is on the engine side.<br /><br />The good news is that although it is 0.5v+ it is only 0.3 milliamps so it doesn't seem like a lot of current. I do hope somebody can shed some light on this. If it turned out to be normal I wouldn't worry about it. Perhaps I'm making a mountain out of a mole hill.

 

[jim dozier]

Re: 97 OMC wiring harness connections

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[rodbolt]

Re: 97 OMC wiring harness connections

jimd.<br /> retest with everthing hooked up and the purple wire from the rectifier assy unplugged. sometimes solid state devices have what is called a reverse or leakage current. if you have a 115 spl which has no regulator unplug the red rectifier leads. with no model numbers its hard to tell which 115 ya got

 

[jim dozier]

Re: 97 OMC wiring harness connections

Rodbolt its a E115SLEU. 1997 Evinrude 115 20" V4 60 degree looper. I'll test it with the rectifier unplugged tonight if its not too cold, the temps are supposed to get down into the low 50's tonight, bbrrrr. I guess the question is if it is comming from the rectifier/regulator solid state leakage does that mean the part needs replacing or that its "within spec".

 

[seahorse5]

Re: 97 OMC wiring harness connections

There is no unplugging of the regulator B+ wire. You have to remove the port side cover to access the starter solenoid, then remove the battery cable and another nut to remove the regulator red wire, then then re-hookup the battery cable. Now you can test to see if there is still a voltage leakage.<br /><br />That small an amount could be just from a film of salt corrosion somewhere.

 

[jim dozier]

Re: 97 OMC wiring harness connections

OK I found the source. With everything else plugged in and the ignition key off I unplugged the rectifer-regulator deutch connector with the purple and grey wires. There is 0.5v+ to 0.7v+ volts coming out of the rectifier purple wire. Sounds like Rodbolt is right, the solid state circuits are leaking. Its not much only about 0.3 milliamps. I am thinking that I'll leave it alone unless I encounter problems with the motor when its running. Does anyone think otherwise?<br /><br />Makes you wonder about electrolysis and such. I'll try to remember to turn the battery main off when I'm not using it. Thnaks to everybody who has helped. Now if my steering cable would just show up I'd be on the water

 

[jim dozier]

Re: 97 OMC wiring harness connections

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[rodbolt]

Re: 97 OMC wiring harness connections

and that is why I reccomend battery switches and the use of them.<br /> on modern outboards with modern electronics its common. its also amazing how big a spart 800 milliamps can produce when hooking up a battery cable.<br /> you would not believe how many harness fires I have seen over the years due to a failed trim or starter relay/circuits when the boat was sitting. sometimes the components will just trigger and start things moving. <br /> most marinas now require on off switches and the use of them.<br /> but I dont see a problem with your rig. its fairly common.

 

[jim dozier]

Re: 97 OMC wiring harness connections

I know I'm never going to put my fingers under the motor bracket again unless I turn that battery switch off It kinda like working under a car without a jackstand.