Alarm goes off when trying to turn key on

[Outdoor Guide]

Hi. First time posting. Not mechanically minded myself. I ran into trouble with my 1984 90 hp Evinrude with the alarm system. Had a boat builder put a new transom on 18" starcraft. The person doing it said the power trim froze up. He put in a used one and it worked great for us the first trip out.
Last Saturday, the shifter control box alarm went off before starting the motor at access area when key was turned on. The tilt/trim wouldn’t work when alarm was going off.
Then later in the day when we got home, the alarm didn’t sound anymore when key was turned on and tilt/trim would raise motor but not lower motor. But the tilt trim would only lower the motor when hitting the up switch on control arm. (Opposite way it should be functioning) Hitting the down switch did nothing. Heard no noise.
This tilt/trim worked perfect just the previous weekend. On Sunday, I turned the key on the Evinrude to check battery power, and the alarm was back on. Today, no alarm, but trim only working one way and opposite of switch.
Do you have any idea what is going on? Do I need to bring to boat shop?

 

[MattFL]

Wiring problem, someone who understands wiring needs to sort it out. Maybe a pinched or bare wire, bad connection, etc..

 

[Outdoor Guide]

Thanks for responding. I am getting very few thoughts on trouble shooting this. We've looked at the wires but have not done any testing - which will be a new adventure to get a meter to test wires

 

[MattFL]

If you want to give it a shot yourself, first start looking for connectors where wire bundles plug together. Take them apart Make sure they are clean and make sure they are put back together tightly. Some dielectric grease will help keep corrosion away. Follow the wires and see if you can find any place they are rubbed through the insulator or pinched or cut. Also check your fuses Make sure they're not blown and not corroded. An electric meter will help but you can do quite a bit of troubleshooting by visually inspecting. Since it was working fine then suddenly not working that makes me think it's likely a connection has come loose or something along those lines.

 

[Outdoor Guide]

Great advice- thanks. We did notice the relay switches in motor had black goo all over - I assume that's the dielectric grease that was put on by someone years ago. I have been so luck with this old Evinrude in having so few issues.

 

[saltchuckmatt]

Great advice- thanks. We did notice the relay switches in motor had black goo all over - I assume that's the dielectric grease that was put on by someone years ago. I have been so luck with this old Evinrude in having so few issues.

If I remember right those old control boxes had a spot where you stuck a small metal thing in and you could set off the alarm. Near the key switch. I think maybe your problem is in the control box. Definitely a tough one. Did you think about taking it back to the guy who put it in?

 

[Outdoor Guide]

If I remember right those old control boxes had a spot where you stuck a small metal thing in and you could set off the alarm. Near the key switch. I think maybe your problem is in the control box. Definitely a tough one. Did you think about taking it back to the guy who put it in?

Greatly appreciate the help. Here's where we are now: Found a single wire that was shorting out where it entered the motor with all the other cables. seems strange as it is just a single conductor that was spliced in the motor to a 7 space terminal strip. we traced the end to Number 5 red on the 7 terminal wiring strip on the motor. the other end of the cable was broken off but cant find where from. not sure if this wire needs to be connected to the battery positive or what it does.?? This is a 1984 90 hp Evinrude. We disconnected the wire where it was shorting and now the power trim works. the alarm is still going off. When we disconnect one side of the 2 conductor wire going to the oil tank the alarm goes off.

 

[saltchuckmatt]

Well, shoot tough one from my seat. Ive had several 90's in that era and a 110 that's basically the same motor. This should have the omc control box that goes back to the motor with what we call the red plug. (Has a big red pull apart plug inside the cowling)from the motor side of the plug it branches out to all of the spots it needs to go. The wires to the trim and tilt go to a tilt solenoid bolted to the motor. Those wires should be green and blue. (Omc mechanics said green means grass or down and blue means sky or up.) Typically that's where you start diagnosing trim/tilt failure. To me if the mechanic replaced the trim and tilt he shouldn't of had to mess with the main harness. It all worked once so obviously something happened. When the outboard steers right and left the harness bends a bunch so you must have broken wires or something. One of the wires you've disconnected must be the low oil alarm. I don't think anyone can fix this one from their chair....again I'd go back to the guy who mounted it.

 

[MattFL]

To clarify:
When we disconnect one side of the 2 conductor wire going to the oil tank the alarm goes off.
Do you meant the alarm starts sounding, or the alarm goes silent? If you mean the alarm goes silent, then perhaps the alarm is related to the oil tank. I'm not personally familiar with that motor, assuming you're talking about the auto-mixing oiler that auto mixes the gas, I seem to recall some of those oil systems had a big tank in the boat and smaller tank on the motor, and the big tank got pumped up to the smaller tank. If yours is like this, make sure it's still pumping and is generally working properly. Maybe it's a legit alarm about something gone wrong with the oil system.