intermittent trim failure on 90hp '99 model merc 2 cyc

wn6ngp

Petty Officer 1st Class
Joined
Aug 12, 2012
Messages
209
s/n OTO87666
The power trim on the motor is very intermittent. I understand how it all works, the relays reverse the polarity to make it run in or out no problem with how it works. Same failure whether I activate it from the motor cowl or from up front. Fails sometimes going up or down. If it would fail and stay failing then I could debug it but now I cannot make it fail again. Anyway, my guess is that its either the brushes or armature in the motor (I hope not) or one of relays or a flakey connection on one of the relays. So now I'm just asking if anyone else has experienced this assuming its a common point of failure. I could just replace the relays and the motor but that's the easy and $$$$ way out.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,514
Ayuh,.... Odds are it's a poor wirin' connection,....

So take 'em apart, Clean 'em,reinstall,'n seal 'em,....
 

wn6ngp

Petty Officer 1st Class
Joined
Aug 12, 2012
Messages
209
I think you are correct. I pulled the bullet connectors apart. I applied power from a separate battery and would never fail. then I plugged the bullet connectors in and I haven't been able to make it fail. It will probably fail next time when I'm getting the boat onto the trailer and if I don't trim up the skag will drag on the road. I am going to tie a string to the those cables so I can quickly pull them out as they are nested amongst other cables.
 
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