Constant horn and other electrical problems

[jdlloyd_iboat]

1990 V-6 XP-150 Evinrude -- Motor and boat sank 2 weeks ago but I was able to raise it and get it running for an hour or so the next weekend. I had to dump the oil reservoir and refilled with new oil and its full. I am running a heavy mix until I know VRO is operating and mixing oil. Electircal problems showed up this week. My warning horn now runs constantly even with engine off and cold (key on). The boat sank such that the throttle controls (where horn is located) never got submerged. My dash and gauges also did not submerge.

I checked temp sensor wiring and have not found anything obviously grounded yet. My trim meter also stopped working (worked Ok first week). I read the forum on this problem with horn and heard that the VRO reservoir level wiring might cause problems. I checked the oil level sensor wiring (2 black wires to sense oil levelin reservoit) one is to ground and the other was already disconnected! (I have had boat 2 years so this just came to my attention). Not sure where this free end should connect anyway. I checked the larger tan wire (16 gauge to low oil switch) and not sure where it is supposed to go either so not sure if it is part of problem or not. Does this somehow read oil pressure at the VRO pump? Coincidentally I also notice my purple wire to the harness connector had been cut by some previous owner (this wire goes to rectifier/regulator and seems to be not part of this problem but might explain why rectifier does not charge battery. I have a SELOC book but does not seem helpful for these problems.

Summary, Horn sounds constantly with engine cold and key on and when engine running. Seems not temperature related. Any ideas? And although not as critical, what should i do with the purple wire in the harness that is severed? Tilt/trim gauge, sensor or receiver problem? How could I check?

Thanks,
Jim

 

[jdlloyd_iboat]

Re: Constant horn and other electrical problems

I believe I have "fixed" the constant horn. It was the cylindrical thing near the VRO pump. I suspect it has failed due to the drenching it go a week ago while submerged. I disconnected the tan wire, taped it off and the horn stopped. I'll need to get a new one I suppose. Still checking to see if oil is pumping while running a mix. Trim gauge still not working. Suspect it got soaked and failed also. I will guess that the starter and the solenoid are probably next. Mean time... back in the water and running fine.

Jim

 

[ezeke]

Re: Constant horn and other electrical problems

If you have a 50:1 premix in your fuel tank, you might as well temporarily disconnect the harness wires running from the VRO to the main harness. That is the approximately 1/2" half round connector with three or four wires.

What you never want to do is disconnect the tan wire from the temperature sensor on the cylinder head, because it is the only warning that you have before the motor burns up. It does not even close and warn you until the temperature is 210? F +/-.​

 

[jdlloyd_iboat]

Re: Constant horn and other electrical problems

Does anyone know what fails on the vacuum switch if it gets wet? It ran for an hour OK after submerged in water. I recoverd the motor and ithe motor started and ran OK. During the end of the run time under load the constant horn came on and would not shut down no matter what I did (even when the motor cold and engine not running with key on). I detached the tan wire on the switch and the horn returned to normal. What has caused the vacuum switch to possibly fail and can it be repaired (a replacement is $120).

I am assuming that vacuum or lack of vacuum triggers the switch to signal less than adequate fuel/oil mix. What is risk of running without the switch after determining the VRO is working properly? I am guessing this is not a smart idea.

Jim

 

[ezeke]

Re: Constant horn and other electrical problems

The vacuum switch is on the gasoline side of the pump and warns you if there is a reduced flow so that you don't pump the engine full of oil. With pre-mix, that concern is dramatically reduced.