Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

The trim on my 90 searay 3.0 mercruiser just completely stopped working. It worked fine a couple of days ago with the exception of the trim up. The trailer button worked but I didnt use it unless the engine was off. Yesterday I took off the trim switch on the starboard side of the bell housing because I found a disconnected wire. I took of the main plate and then the screw where the wires when into the trim switch. I looked around to see if it was repairable but with no luck. So I put it all back together and when I went out today to go for a ride the trim doesnt work at all. Nothing coming from the motor. I was wondering what I did to completely break the trim on the boat? Any help would be greatly appreciated.

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

down and trailer should work anyway. check all power and ground connection at the pump and battery..
Test with a jumper from the battery to the blue (up) and green(down) motor leads.

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

Also, while your in there checking voltage. There is a fuse in a J-clip. Red wire/purple chaser, black fuse holder. Pull straight apart, don't twist! You'll hate yourself if you do.
That fuse feeds the switches on the handle & does blow when trim limit harness shorts to ground.

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

Hey Bt,
I checked the power wire from the pump to the battery and all is fine. I disconnect my battery after each use. Would this have any type of effect on the pump? My other question is, if the jumper does not work for either, would it be the solenoids? It's hard because Im trying to make head and tails with the diagram online to the actually pump. Btw I checked the fluid to see if that may be the problem but it's full. Is there any other fuses on the pump itself or located somewhere else that feeds the pump?




Hey Pete,
I thought your answer could help me best because of the wires on the trim switch (starboard side) may have touched but I believe the battery was disconnected when I preformed the work. I always lower the outboard when i come home to help with the bellows. Would that become a problem in itself? When Im checking power for the trim switch, I should have someone checking the wires on the outboard while I try and trim it, right? I know it's a electrical problem, I just cant find what fuse may have blown. I know this because it worked completely fine with no problems (except the trim up) and now not nothing happens when I push trailer, trim up or down.
I just located the 20 gauge fuse facing the bow that I checked. It was not burnt out. I was been looking at the diagram for that pump and was wondering if the 110 amp fuse could be the problem?

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

You can bypass the limit switch inside. Look closely just under the "steering lever" you'll see 2, two-wire harnesses. 1 of them is sender for gauge, the other is "trim limit". The limit harness has a blue sleeve & brown sleeve on one each of the wires. Unplug & plug the "pump side" together. This eliminates the switch outside.
Try this see what you get. I'll be around

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

So by bypassing the limit switch, I have no need for the switches on the bell housing? http://www.boatfix.com/merc/Servmanl/6/6A5R3.PDF is there any way you may be able to point out which harnesses you are talking about?
Just curious, if this does work, will my trim up/down/trailer all work?

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

Very last page. Inside the boat, near the pump itself. 2 black wires that come thru the transom, 1 wire has a purple band & the other has a blue band. Connect (female side) these together. If the fuse is not blown & switches are operating, the drive will go up & down.

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

double check again for a positive wire and the NEGATIVE wire. you say you umhook the battery, maybe you missed the ground for the pump.using the jumper from the battery to the pump leads should make the motor turn regardless .may want to try a neg. jumper to the battery. sometimes wires get corroded open under the insulation.make the insulation feel lumpy.looks good on the outside but no connection inside.

Re: Mer Cruiser Alpha 1 Outdrive Gen. 1 Trim Problem

Hey,
I Just checked the Neg (it wasnt tight) and now the motor clicks when using the trailer button. Any suggestions on why that may be the case?