Unreliable VP power trim

[petem]

The 'up' control for our starboard leg works infrequently. We've changed the dashboard switches and the relays. 'Down' works fine so I don't believe the fuse can be at fault. If we clean the contacts in the relay socket it works for a few hours but stops working after that.

My thinking is that the relay socket needs to be replaced. Has anyone done this?

Anyone got any other suggestions?

 

[jon and michie]

Could it be the relay on the way out ? - if twin engines you could try and swap them over to double check

 

[petem]

Could it be the relay on the way out ? - if twin engines you could try and swap them over to double check

Thanks. I've swapped the relays and the issue remain with the 'up' action.

 

[TK Blue MAX]

Could it be something mechanical, rather than the electrics, just a thought, have you verified that the motor is working?

 

[rafiki_]

Thanks. I've swapped the relays and the issue remain with the 'up' action.

Are you sorted on this Pete?

 

[jakew009]

The 'up' control for our starboard leg works infrequently. We've changed the dashboard switches and the relays. 'Down' works fine so I don't believe the fuse can be at fault. If we clean the contacts in the relay socket it works for a few hours but stops working after that.

My thinking is that the relay socket needs to be replaced. Has anyone done this?

Anyone got any other suggestions?

Next time it happens you really need to run a jumper wire, bypass everything and see if the leg moves.

If it moves you know the fault is in the control circuitry.

If it doesn’t move the fault lies elsewhere.

Your description makes very little sense electrically. There is no reason why cleaning the relay would make it work for a few hours before stopping again unless you are doing a cr*p job of cleaning it.

 

[oldgit]

Leg on a SC35 refused to move recently, simple fix to get home was a bit of wire direct from leg motor to battery to lower it.
Replacing a relay cured the problem, however the removed relay appeared to work perfectly when checked with a multi meter.

 

[petem]

Your description makes very little sense electrically. There is no reason why cleaning the relay would make it work for a few hours before stopping again unless you are doing a cr*p job of cleaning it.

Don't rule out poor cleaning!

But it's a lot harder to clean female plugs than males (I may try some miniature diamond files).

 

[kashurst]

Don't rule out poor cleaning!

But it's a lot harder to clean female plugs than males (I may try some miniature diamond files).

There comes a point when you can "clean" connectors too much. Typically the sort of connectors used on boats are tin plated brass. The tin is there to try and minimise atmospheric corrosion. If the assembly is a tin plated male into a tin plated female all is good usually for a long time. Where the tin plated parts touch properly the tin tends not to corrode and maintains a good electrical connection. If you take the connection apart the tin is pretty soft and "wipes" clean again.
Conversely sometimes you may come across an unplated brass male into an unplated brass female - in a car OK ish in a boat not a good idea.

What you don't want is an unplated brass plugged into a tin plated connector - that will corrode pretty quickly.

If you have got to the point when your are sanding/filing contacts it's time to replace them with new. If the sanding/filing go through the tin plating there is now a brass on tin connection. This will encourage further corrosion and weaken the mechanical force that clamps the contacts together. If this will get you through a holiday/trip brilliant, but probably worth putting replacement on the winter job list.
The other thing you can try is gently squish the female connectors with pliers to increase the contact force.

Either way good luck.

 

[petem]

There comes a point when you can "clean" connectors too much. Typically the sort of connectors used on boats are tin plated brass. The tin is there to try and minimise atmospheric corrosion. If the assembly is a tin plated male into a tin plated female all is good usually for a long time. Where the tin plated parts touch properly the tin tends not to corrode and maintains a good electrical connection. If you take the connection apart the tin is pretty soft and "wipes" clean again.
Conversely sometimes you may come across an unplated brass male into an unplated brass female - in a car OK ish in a boat not a good idea.

What you don't want is an unplated brass plugged into a tin plated connector - that will corrode pretty quickly.

If you have got to the point when your are sanding/filing contacts it's time to replace them with new. If the sanding/filing go through the tin plating there is now a brass on tin connection. This will encourage further corrosion and weaken the mechanical force that clamps the contacts together. If this will get you through a holiday/trip brilliant, but probably worth putting replacement on the winter job list.
The other thing you can try is gently squish the female connectors with pliers to increase the contact force.

Either way good luck.

Thanks K. We've had the mechanic out to look at the relays a few times now. I totally agree with your point that there's only so much connector cleaning that can be done which is why my post was suggesting replacement of the connector. I didn't look at the wiring too closely as I have limited enthusiasm for crawling down the side of my engines in 32 deg heat but I vaguely recall that the connector that the relay plugs into is on a shorter bit of loom that plugs into the main loom via another connector. At least that would enable me to replace the connector in comfort instead of lying on my back. Hopefully that makes sense!

 

[Portofino]

Normally quite sceptical of alleged wonder treatments but this stuff Is truly great for intermittent electrotwackery faults , involving connectors . Whereby you have already passed the wallet emptying parts throwing stage replacing stuff , and there’s no hair left to pull out .

Stabilant 22 5ml Field Kit - Race Glaze

Used it on notorious Italian electrics on that well known F 1 brand .

It works .See the blurb .

 

[Portofino]

There comes a point when you can "clean" connectors too much. Typically the sort of connectors used on boats are tin plated brass. The tin is there to try and minimise atmospheric corrosion. If the assembly is a tin plated male into a tin plated female all is good usually for a long time. Where the tin plated parts touch properly the tin tends not to corrode and maintains a good electrical connection. If you take the connection apart the tin is pretty soft and "wipes" clean again.
Conversely sometimes you may come across an unplated brass male into an unplated brass female - in a car OK ish in a boat not a good idea.

What you don't want is an unplated brass plugged into a tin plated connector - that will corrode pretty quickly.

If you have got to the point when your are sanding/filing contacts it's time to replace them with new. If the sanding/filing go through the tin plating there is now a brass on tin connection. This will encourage further corrosion and weaken the mechanical force that clamps the contacts together. If this will get you through a holiday/trip brilliant, but probably worth putting replacement on the winter job list.
The other thing you can try is gently squish the female connectors with pliers to increase the contact force.

Either way good luck.

No need to file anything.See my post #11

 

[petem]

Thanks K. We've had the mechanic out to look at the relays a few times now. I totally agree with your point that there's only so much connector cleaning that can be done which is why my post was suggesting replacement of the connector. I didn't look at the wiring too closely as I have limited enthusiasm for crawling down the side of my engines in 32 deg heat but I vaguely recall that the connector that the relay plugs into is on a shorter bit of loom that plugs into the main loom via another connector. At least that would enable me to replace the connector in comfort instead of lying on my back. Hopefully that makes sense!

Thanks for the link. I actually sell a similar product (DeoxIT) with an equally good reputation.

 

[tico]

Was going to suggest DeOxit but you forestalled me.