Merc Trim Pump Electrical Connections

[Rod Holder]

1978 Mercruiser 470<br /><br />Hi,<br />My trim pump was acting up (very slow motor, then would speed up) and I suspected something was going on with the brushes. I disconnected all the electrical from the assy and removed the motor.<br /><br />Good news, stuck brush.<br /><br />Bad news, now all it will do is BUZZ (kinda like a beard trimmer and the ground wire gets hot) and like a real gomer, I failed to take a picture of the wiring and I suspect I have mixed up at least one.<br /><br />If someone has a picture or schematic I would be most thankful !!<br /><br />My manual only shows a partial and the relay looks different.<br /><br />Thanks........RH

 

[I/O WALDO]

Re: Merc Trim Pump Electrical Connections

Hot ground,=bad/stuck motor,regardless of wiring.(green/grass=down...blue/sky=up)

 

[Rod Holder]

Re: Merc Trim Pump Electrical Connections

Thanks Waldo, <br />I'll take it back out and try and find if it is binding.<br /><br />The motor has two wires. I would like to test the motor before re-installing onto the pump housing to see if it is ok and if the problem is with the pump. <br /><br />What would the connctions be to fire up the motor ?<br /><br />Thanks......RH

 

[Don S]

Re: Merc Trim Pump Electrical Connections

It's a reversable motor. One lead on + one on -, then turn them around to make sure the motor runs in opposite direction.<br />Do you have a single or dual solenoid on your setup?

 

[Rod Holder]

Re: Merc Trim Pump Electrical Connections

Thanks for the info !<br /><br />Tested the motor on it's own and it was fine (both directions)<br /><br />Turned out I had the main ground wire connecting to the one of the larger soledoid posts (mostly due to the large size of the elec. connector and it threw me for a loop). It should have been on one of the smaller posts. If a single soledoid setup has two large main posts and two smaller switch posts, then I have a single.<br /><br />Outdrive raises like a Viagra crazed maniac !!<br /><br />Ready for more Ling Cod action !!! Won a tourney last weekend and it paid for the $ 3.25 gal in town gas (uggghhh !)<br /><br />Thanks guys.........RH

 

[I/O WALDO]

Re: Merc Trim Pump Electrical Connections

Never seen one like dat!The ones I have serviced with the black phenolic-type pump-resevoir have blue and green motor wirez,and a black motor case ground.The green goes to the small term. block and the blue goes to the non-hot side of the relay and the ground goes to the grounded term on the relay!

 

[Rod Holder]

Re: Merc Trim Pump Electrical Connections

You are absolutly right Waldo. Me thinks I have a "custom" wiring setup for the power and ground as the battery only powers the pump and my electronics. The order you describe is same as mine except I have a ground running from neg battery post to the grounded terminal on the relay. I messed up by thinking that ground wire should go to the non-hot side of relay along with the blue motor wire (conflict of interest ha ha)<br /><br />Always learning and the price was right !!!<br /><br />Have a great weekend.

 

[I/O WALDO]

Re: Merc Trim Pump Electrical Connections

Still tryin to git my mess wet,mechanically ready.now cosmetics!(89 chaparral 278xlc family cruzer witha 502 efi mag. FUN,and very suprising to other boaters!)ENJOY!!