1988 OMC Cobra Tilt/Trim Doesn't Work

Greg007

Recruit
Joined
Jan 29, 2015
Messages
4
Hello, my name is Greg. I am in the Navy so you think I would know more about boats than I do. I have a 1988 OMC Cobra 5.0. The trim will not work in either direction. Had the same problem last April. Took the switch apart, lubed it and bought a new battery (needed one anyway). It worked for the season although I would get a shock every now when I was wet and engaged the trim switch. Also, towards the end of the summer, sometimes I would engage the switch and it wouldn't work until I cranked the engine. Now it doesn't work at all, but both solenoids click when I engage the switch. The boat has been sitting for about 5 months while I've been out to sea.
This is what I have tried so far:

1. Charged battery. It is reading 12.6 volts
2. Cleaned all terminals (battery, solenoid in and out cables)
3. Jumped the wire directly to the motor. I hope I did this right. Unhooked the large blue wire and the large green wire from the solenoid and ran a wire from the positive battery post to the each of those wires at different times and nothing happened. I also unhooked the large red wire going into the solenoid and connected it directly to the large blue wire using electrical tape. Nothing happened.
4. Tested the amount of volts going to solenoids. Both were around 9 volts which made me suspicious about the switch. But...
5. Tested the about of volts going from solenoids and both were around 12.2 volts.
6. Rigged a separate switch going from battery to each of the solenoids. Nothing.

Would you have any advice? I was going to take the remote control handle apart to check the switch, but the multimeter showed 12 volts leaving the solenoid so I don't know if that will help. My next thought is to take the trim motor off and test it, but it is in a hard place to get to. Any advice on getting that thing off?
Thank you for any help you can give.
 

Boat Doctor1

Petty Officer 2nd Class
Joined
Sep 29, 2012
Messages
123
corosion!!!!!!!!!!!!!!! look in the area og a red (small) fuse connector on engine-look 4 corosion!! it should be a 50 amp!!very small fuse! also look in starter area on starter for coroded wires where battery is connected-be sure to disconect battery 1st!! Trim motor is acessable easily?? hah -with 1/4 " drive socket stuff! yes its apain!! You cam=LIGHTLY slap that trimmotor with a hammer- with switch depressed- to see if it works? Remember =trim motors are placed near the bilge area too=Corosion!!
 

Greg007

Recruit
Joined
Jan 29, 2015
Messages
4
Thank you for the reply. I didn't know there was a fuse involved. I will check for the fuse and then bash the motor with a hammer (lightly).
 

Greg007

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Joined
Jan 29, 2015
Messages
4
Unplugged the trim motor and wired the blue wire to the pos terminal of the battery. Wired the black cable to the neg terminal of my battery. Sparked a lot and started to melt the jumper wire, but the motor didn't work. Any suggestions on taking out the motor? It's in a bad spot.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Don't you have blue and green wires coming out of the tilt motor ??
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,924
Test light?
Have someone at the controls.
Hook light to a ground.
Then touch wire(either one) and have the helper operate the switch either way, up or down.
If you have voltage through the solenoid to the motor.
Then test the other wire.
Voltage both wires? No operation? Motors bad.

Test at the solenoid output lugs.

The OEM motor is available but $300+
There is a rebuild kit 0984961 Seal/ brush kit. $85
Good luck.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Unplugged the trim motor and wired the blue wire to the pos terminal of the battery. Wired the black cable to the neg terminal of my battery. Sparked a lot and started to melt the jumper wire, but the motor didn't work. Any suggestions on taking out the motor? It's in a bad spot.

Ayuh,... Sounds like the motor is seized,.... Pull the whole trim pump out,....

It's much easier to work on, on the bench,....
 

Greg007

Recruit
Joined
Jan 29, 2015
Messages
4
Thank you all for the help. Motor is bad. Ordered one from DB Electrical in TN for $73.00 and free shipping. Will get it sometime today and put it on this week. I will post if it works or not.
On another note, my trim is stuck in the down position. I read where you unscrew the manual release valve and can lift the trim manually. I unscrewed the valve, but still couldn't get the drive to move up manually. Do you have to take the screw all the way out? Any suggestions? I would like to be able to use this if I need it at the boat dock someday. Thanks again.
 
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