Need help troubleshooting to isolate problem to trim motor or electircal

[deerhuntre]

I'm confused trying to follow the service manual process of using a battery to test the UP trim motor. I'm not sure what 'block' or connector is what so I'm not sure which blue wire to get from where?

On my pump there's a solenoid and there's also a harness plugged in just below the solenoid to the pump with a blue wire.

Please clarify which blue and black wires to disconnect to hook to a battery to see if the motor runs in UP position.

Thank you!!

 

[Don S]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

What are we working on? other than "A Trim motor"

 

[deerhuntre]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Sorry for the brain fart....Its a 1972 Mercruiser 165 hp with an unidentified outdrive because I cannot find any serial numbers anywhere and there are no stickers on the sides either. I think photo's will help, so I'll get them posted shortly.

 

[Don S]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Let's call it a MC 1 drive, since that is the only drive that came on the 165.

If the pump is still on the boat, forget about testing just the motor. Go to 7A look at the wiring diagram on page 7A-7. The terminal block is on the pump housing, and the 2 green wires hook to it. The wiring diagram will also show you the blue and black wires.
Look through that section completely.

 

[deerhuntre]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Thank you, Don. This is very helpful. What I wanted to do is perform the test on page 7A-19. I'm just finding it confusing to follow step a. and b. on 7A-19. Is the black wire they are talking about the one from p. 7A-7 that goes from the solenoid to 'Connet to -12v'? And, the blue, is it the one that goes from the solenoid to the pump motor via the 'squiggly' line?

And, the other strange thing: The previous owner had a metal hose clamp tightened around the harness plugin at the pump. I wonder if there's a short or something that was attempting to hold together?

 

[cr2k]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

The hose clamp is factory.

 

[deerhuntre]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

OH...I guess I will have to go fish it out of the trash. Thanks!!

 

[Don S]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Is the black wire they are talking about the one from p. 7A-7 that goes from the solenoid to 'Connet to -12v'?

Yes. Grounds always end at the battery.

And, the blue, is it the one that goes from the solenoid to the pump motor via the 'squiggly' line?

Yes.

The previous owner had a metal hose clamp tightened around the harness plugin at the pump

.

The clamp is just snugged up around the connector to keep it waterproof and secure. DO NOT OVER TIGHTEN or you will damage the connection.

 

[deerhuntre]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Results of test: I connected the battery to the pump motor, black to neg and blue to positive. The motor did not turn at first, but then I tapped the pump motor housing on top and the motor began turning, first slowly, then picking up speed.

Please let me know what this may mean and what I may do to further diagnose and fix. My manual has a step by step for the pump motor and I'm going to start reading it, but before I begin taking things apart, I'd love to hear your advice and recommendations!!

Thank you!

 

[Don S]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Results of test: I connected the battery to the pump motor, black to neg and blue to positive. The motor did not turn at first, but then I tapped the pump motor housing on top and the motor began turning, first slowly, then picking up speed.

That means the motor has issues. Probably full of rust and corrosion. No doubt, you will need a new one.

 

[deerhuntre]

Re: Need help troubleshooting to isolate problem to trim motor or electircal

Thanks, Don. Now to figure out which part number/model to get....