Mercruiser 1987 Alpha 1 trim pump

D

ddurand

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Member
Joined
Jun 20, 2001
RO Number
5015
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837
My trim pump seems to have died. The relays click in trim in/out and trailer but no motor sound.

I assume I need to replace the motor? What is the easiest way to pull only the motor off? There are 4 bolts on the top of the motor will that allow the motor to be removed.

I also checked for +12 on the solenoid output and with a jumper wire gave the solenoid output +12.

Best place to get a trim pump motor?
 
I would do a thorough troubleshooting - I don't know all the things to check off the top of my head, but if you google you find it pretty easy. I do know there are multiple things that can make the pump motor appear to be bad - there are solenoids controlling up down AND the trim limit switch on the outdrive. More often than not there is a problem with the limit switch and / or connection / corrosion issues with the wiring. I have rarely heard of the motor failing, it's usually wiring or the limit switch. Hate to see you buy a new motor when it's not needed.
 
That the solenoids are clicking means they're working. You have to check the high amp contacts. Remove and scrape or sand. It's possible to show continuity in the contacts but not have a solid enuff connection run the motor.
 
Disconnect the wires from the solenoids and connect jumper wires and see if the motor works. My boat is an '88 and I replaced my trim motor last year. I found it easier to remove the pump from the boat to change the motor. I also cleaned the oil reservoir. It had an inch of sludge inside on the bottom. After that the oil stayed clean. Got my motor from EBasic Power.
 
I have run a clip lead from the red (+12 V) coming in to the trim to the control wire going to the solenoid. The solenoid clicks. I take that same clip lead (still connected to +12 V) and touch the output of the solenoid and nothing. No spark, no motor, nothing. I cannot see it being anything but the motor.
 
The trim pump is one of the few things I ain't taken apart. I just go to my local merc guy and get the whole trim pump for #100. It's the newer type with the white plastic reservoir instead of the old kind with the metal reservoir in the bottom
 
This is to test using the solenoids to operate the motor
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Next test motor with jumpers from the + and - of the battery. negative to the bracket and + to the large blue motor wire (up) and to the large green motor wire (down)
Power for the solenoids that operate the motor comes from the brass buss bar. hearing the solenoids click means either the solenoids contacts are bad internally, the motor is bad, or there is no current to operate the motor.
 
I have tried the mentioned tests and nothing from the motor.

I see some motors on EBAY for $65, but a Sierra is double or triple that. And I am sure Mercruiser would even be more.
 
Then most likely the brushes are stuck or the armature is just dirty. both can be repaired.
 
I found a local auto electrical shop in Schenectady NY that will repair or rebuild it. (I hope). I would rather have it done and work flawless for many years than save $50 now. Its also a hassle to take out.

The rusty mounting plate is still screwed to the boat. I see that sell SS ones. I could remove mine and paint it.
 
At least for the newer ones, there's a stainless steel one. Used to run $100+ but I'm seeing it for about half that here
http://www.amazon.com/Trim-Mounting-Bracket-Stainless-Steel/dp/B0084Q0Y76 and about the same on eBay. When I got our boat I thought the bilge was full of leaves. It was actually full of Trim Motor Bracket Flakes. The SS ones were $150 back then, but mechanic was willing to loan me one to use as a template for making one out of sheet aluminum and that has worked out fine.

I do NOT know if you can easily adapt the late model bracket (for pump with plastic reservoir) to your early pump. Probably with drilling new holes and you have your bracket as a template. BUT!!! easier things to do than drill a bunch of holes, accurately, in SS.
51-13L%2BcFwL.jpg
 
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