1989 100 gt trim problems

Hey yall, having problems with the power trim.
a week ago we were fishing and my motor seemed like it was struggling to trim up, it progressively got worse and then just stopped all together.
It didnt have any trouble trimming down at all.
a little later that same day it started working ok but you could tell that it was laboring going up.
got it loaded on the trailer and got home, I gave the trim motor a few taps with a wrench and it acted brand new again.
Well I assumed since all the wiring looked good, no melted or dis colored wire that it was the trim motor going bad.

well a couple days later of it just sitting in the drive way, the motor starts trimming up by itself, apparently it had been doing it for some time because my wife said that the trim motor was so hot that she couldn't hold her hand on it.

anyone have a clue as to what the issue could be? Could it be the trim motor? Thanks for any help

If it went up by itself You probably have a broken trim switch or or a bad trim relay. Could be some bad insulation on the wires somewhere to cause that. I would start at the relay first. From what you describe the relay could cause both things
If that motor got that hot it may have toasted it.

A more description on what type of boat it is on and location of the trim switch would help a lot.

Pics are always good to send also.

The trim relay box is like this one hope this link works

http://www.ebay.com/itm/1986-1992-70...423a42&vxp=mtr

It's a 1989 johnson gt 100 outboard

It has two trim switches, one on the cowling on the motor and one on the throttle. It has nissan controls. I havnt had the motor long, I purchased the boat and motor from LSK in lebanon Mo. I noticed it had new wiring and a new trim switch on the cowling when I purchased it.
what confuses me is that it worked perfect after tapping on the trim motor, that's what made me think it was the motor going bad. (Kind of like tapping on a starter thats on its last leg)
And I kind of figured that its possible that if the trim motor was going bad, that there could be a short in the motor itself causing it to trim up by itself.

I left something out on the first post, after I had got it home it wasn't wanting to go up or down until I tapped on the motor.
and both relays were clicking, I don't know if that's a sign of them still being good or not

First thing, the motor can't do anything on it's own, there should be no power to it at all until a button is pushed. First you have something closing in one of the switches or the wiring shorting together to feed power to the motor. Relay has to be activated by power from switches to work be a real fluke for one to short or close by itself. Clicking relays don't always mean they are working properly. Usually when your motor runs after tapping on it means the brushes are sticking or armature is dirty from brush dust. Most can be disassembled and clean fairly easy but if it has gotten hot several times it also have a magnet that has come unglued inside motor. But first we need to find where power is coming from.
#1 check under cowl and check all wiring to add on switch, make sure nothing under ther is shorten switch connections, then check the wiring run for anything rubbed together. #2 Then trace wiring back to switch in your hand control. It's going to be a process of elimination. In a situation like this I always try to eliminate any add on stuff like the cowl switch. And any connections where it was spliced in.

#3 once you determine what is causing the problem and repair that, if the motor is bad it can be rebuilt. Jones trolling motor a board sponsor on here could probably rebuild it or might be able to get you a replacement a lot cheaper than factory.
Hope this helps some.

Thanks to you both for the information, sounds like I have a date with a volt meter:-)
it'll have to wait until July but I'll post back with what I find.
if I don't find any shorts or bad wiring, can I swap relays to see if it trims down by itself? That would surely tell me the up relay is bad correct?

Yes.