Mercruiser 140 Trim Pump Selenoid Wiring

ronsschultz

Cadet
Joined
Feb 24, 2010
Messages
9
I recently bought a 78 Seawirl with a Mercruiser 140 hp stern drive. Having problems with the Trim Pump. Appears the previous owner messed up the wiring and there was a dead short, not to metion the selenoid is bad. Can anyone tell me the correct wiring? I have ordered a repair manual and hoping it will contain what I need as well.

From the switch there is a Red (Hot), Green, Purple, Blue

I have Blue and Green coming from top of pump.

Top of pump also had a post for what I think is for a negative cable.

I have two wires coming in from (I think) the trim limit switch, but the are not color coded real well. Someone tried to color them with a blue and red it looks like.

I have positive and negative cables from battery.

I have only been able to find a diagram from a Prestolite Trim Pump, but it has two selenods, with this only has the one.

Any help would be greatly appreciated. I have found tons of useful information in this forum already.

Thanks
Ron
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 140 Trim Pump Selenoid Wiring

Go to the Adults Only section of this forum and find the right manual for your engine. I know it shows the single solenoid system in there....

attachment.php


Wiring:

Blue -> up
Green -> down
Purple -> trim limit switch

On single solenoid system, the green from the control panel goes directly to the green on the trim pump motor.

Chris.......
 

Attachments

  • trim pump wiring.jpg
    trim pump wiring.jpg
    87 KB · Views: 18

ronsschultz

Cadet
Joined
Feb 24, 2010
Messages
9
Re: Mercruiser 140 Trim Pump Selenoid Wiring

Chirs,

Thanks for the diagram, this is exactly what I needed. Sure enough they had it wired wrong, however still apears my selenoid is bad, as the terminals with the black, blue from pump and blue from switch all have continuity. I dont want to hook the battery up and test, as once I hit the up ill send current down the blue wire which is shorted with the black and blue from pump. Looks like replacement is less then $20.00 so, hopefully this will be a cheap fix. Thanks again...
Ron
 

ronsschultz

Cadet
Joined
Feb 24, 2010
Messages
9
Re: Mercruiser 140 Trim Pump Selenoid Wiring

ALL FIXED!!. Got a new selenoid and rewired correctly. Also pulled down the manual for my engine. Thanks for the info!!!! Just need to change out all the fluids, lube and do tune up and Im on the water.

Ron
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 140 Trim Pump Selenoid Wiring

ALL FIXED!!. Got a new selenoid and rewired correctly. Also pulled down the manual for my engine. Thanks for the info!!!! Just need to change out all the fluids, lube and do tune up and Im on the water.

Ron

Glad to be of service.... Also happy to see someone knows what to do when they have acquired a new toy... :D:D
 
Top