Running Great! Then WTH!

First Thanks! To those who helped me with my high idle! I received some very informative help with my 70 Johnson when i had an high idle. Ended up being a small air leak which I found and fixed, that brought my idle down to a grand at idle, 900 in gear,so thats liveable for now. So im cruising at 3/4 open throttle, enjoying my new work i have down on my motor, it was well worth it! Then i hit the trim button to get some more plane a few seconds later i herd the roar of my prop out of the water! Wtf! I hit the key and it was trimming up on its own! I reached down quick under the console and pulled the cable off the battery. My motor had trimmed up on its own! I put the cable back on an Nothing happened. So the trimmed worked to get it down again so I started the engine and made it back to the ramp. Without no further problems. Got her home flushed her out hit the button on my motor to trim the motor up and it wouldn’t stop! I pushed on a relay and it stopped. I have basically enjoyed my motor for 4 hrs! Ok so i pulled the relays and there is a brown goo all over the prongs and the relay box! Is it electric grease thats old? Regardless i need help again guys? How do I Trouble Shoot this PTT without taking stuff all apart? How do I approach this gentlemen? Ive seen on line where there is similar problems. To help anyone who knows it a 98 Johnson 70 original ptt. I bought new relays. Both switches on motor and throttle handle look clean and are clicking properly no corrosion as far as i see it. There is as i have mentioned a brown goo all over the relay box! Its all over the prongs to the relays, its a mess!

The brown " goo " is put on in the factory !

Yes thanks I figured that but, was it a wwhit dielectric grease to start? Does it turn brown from dirt and oil residue over the years? Could it be causeing my ptt Problems?

The " goo " is NOT your problem here.-----Overthinking on your part.

Ok I thought it might cause grounding out. So do you know of a procedure to troubleshoot this problem?

Also if it helps. I went out and bought 2 new relays. I should have tested the old ones first, i tested the relays after the fact, they are good. Over thinking again, i guess. Im getting this trim problem with both up and down. Switching relays sometimes works,and sometimes doesnt. Right now its working, its an intermediate problem here. It was a scary thing yesterday so i want to fix this thing.

Since you've already replaced the relays, my first act would be to temporarily disable/disconnect the PTT switches after you have the tilt angle where you can leave it alone.... one switch at a time if more than one exists.

That would consist of simply rigging the red 12v power wire leading to the switch with a quick disconnect setup... a little time involved but no rocket science mentality required.

The PTT switch has been known to look practically new but failing internally.

Trim switch on the lower cowling.-----Pull the red wire plug and leave it disconnected for a few trips.

Thanks Joe, i just talked to an OMC mech, and a lot of what I described he seems to think the problem is coming from the switch box. He said they sell a new type of switch box thats all composite that it is closed unit. I do a lot of trailering back and forth im over not the best of roads sometimes i use the ptt system quite often. Im just wondering even though I wouldn’t use it, if a rattle or vibration would set it off, or i should say On! All that work and learning about this motor and now this. Lol cant win sometimes. I was hoping to do a testing procedure to narrow it down.

That applies to that year motor, replacement switchbox thats a contained composite setup. 129$ So im told.

Answer me this, if you can if I disconnected the switch on my cowling would the switch on my throttle handle work?

Disconnecting either PTT switch would not interfere with the operation of the remaining PTT switch.

Thank you Joe.