Tilt/trim pump

Cv23okoboji

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Jan 30, 2024
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I hope someone can help. I have a 1983 R Mercruiser in my CV 23 Carlson. After boating for a while my drive will not raise. Seems after a while it will work again. Never a problem on the trailer. Only 90 hours on boat and motor. Connections are all good. Any recommendations for a very intermittent problem?
Thank you
 

alldodge

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Welcome
In most cases, it needs to have the problem to find it

My guess is something is getting warm and loosing contact including the grounds. Many don't look closely at the grounds but that is the other half of the connection. Could be the switch in the handle, mine went bad

A test light could narrow it down once it stops working
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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remove all connections, clean with 150 grit until they are clean enough to have your mother-in-law eat off them.
 

Bondo

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Connections are all good.
Ayuh,.... I agree, til All the connections are taken apart, cleaned, 'n reassembled, you can't be sure of that,....
'n that is the place to start,....
 

Scott06

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After you clean all the connections if it is still happening trouble shoot the solenoids or relays. You can swap the up one for down and see if the issue follows.
 

kenny nunez

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The wire colors are simple, green as in grass down, blue as the sky for up.
If the pump runs at full speed and the solenoids just click when the pump does not run then there is good chance the solenoids are at fault. If your pump has the miniature style solenoids they are not as good as the earlier large style that are found on Ford cars and trucks.
As previously posted the switch in the control handle is another source of problems with the trim system.
 

ROY WILLIAMS

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Aug 8, 2022
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I hope someone can help. I have a 1983 R Mercruiser in my CV 23 Carlson. After boating for a while my drive will not raise. Seems after a while it will work again. Never a problem on the trailer. Only 90 hours on boat and motor. Connections are all good. Any recommendations for a very intermittent problem?
Thank you
so the outdrive of the up/down ...... so the electrical motor brushes take it off and the rusted the brush holders cleaned it .....
my 1978 MCM470 did the year ago outdrive upper and the cleaning the brush holders ......rusted it ...
 

harringtondav

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May 26, 2018
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2,438
FYI. The two trim solenoids and the starter slave solenoid were the same parts in my past 1996 4.3LX power package.
Useful in a pinch.
 

dingbat

Supreme Mariner
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Nov 20, 2001
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15,503
An electrical circuit shutting down when warm is a thermal issue, especially if a motor is involved.

First thing I’d check is to see if the pump is getting warm/hot, tripping the overload or a relay is getting hot and opening up on you.

You can pretty quickly eliminate a ground ground problem by checking the resistance between the ground wire/connection on the trim pump and the battery. A good ground connection will read 0.5 ohms or less.

On the power side, a voltage drop test is appropriate. Measure battery voltage as your baseline. Then measure the voltage on the pump when actuated. A drop of 0.1 volt or more signifies a problem.

If voltage drop is too high at the motor, go back and run the test on the power input to the relay. This will eliminate the wiring between the relay and the pump.
 

QBhoy

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Mar 10, 2016
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8,310
Hi,
Should I be thinking along the simple things to try first...this is the order I would be attacking things;
I would swap over the relays and see if the problem repeats itself (obviously do this when in the same comparable circumstances, as to when it is known to cause issue)
If you can and it's possible you could also swap over the blue and green wires...the above thinking applies again.
The above will then tell you where to go next.

If the issue is repeated, but for the opposite direction, then its the relay itself
If the issue is as it was previously, it is most likely a continuity issue, or lack of it !
Start with looking to see if anything electrical and related is hanging loose or open ended, into the bilge or bilge water.
The above ruled out, Check the continuity of the earthing circuit from there to a known earth source or battery earth.
I would also just ensure the power feed to the pump is healthy. You could even supply a known source of 12v direct to the pump in each direction (while allowing each relay to make it's circuit), just to make sure that she's healthy both ways there.
The above might even lead you to the trim switch or its circuit being to blame.

I suppose it might also be handy to know if it just won't even try to trim up at all and all seems dead and silent..perhaps only a click ?
Or does she seemingly try to operate with the pump at least sounding like it is making an effort ?
assuming the oil is to level and no sign of water in there ?

Hope some of that might help you. Sorry if it has been ruled out or covered before me sticking my oar in !
 
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