Power lift for engine bay hatch

[Trident]

My friend has a Beneteau Prestige 34 with a hydraulic electric ram to lift the hatch over the engines (which includes moulded seats etc)
This works intermittently - often just trying the switch several times works, sometimes you need to haul the hatch up manually and let it down and it starts working and sometimes when half way up or down it will stop and if you reverse direction for a second a try again it then works.

There is full 12v going in to the motor and that is stable. So does anyone have an idea please of what might cause this issue and if its fixable or should I just replace it for him with a new one - which is what he asked me to do but if there's a fix even better

 

[fredrussell]

Have you checked EVERY connection (from battery to motor for corrosion? If so, try bypassing switch to see if it’s knackered.

 

[Trident]

Have you checked EVERY connection (from battery to motor for corrosion? If so, try bypassing switch to see if it’s knackered.

No but then there is a stable current over 12v when in use, and when trying to be in use but not working - measured at the wiring going in to the ram so switch and wiring joins etc should not be the problem or I would expect to see a current drop or intermittent current at the unit

 

[billskip]

No but then there is a stable current over 12v when in use, and when trying to be in use but not working - measured at the wiring going in to the ram so switch and wiring joins etc should not be the problem or I would expect to see a current drop or intermittent current at the unit

Do you mean stable voltage?or are you actually measuring current?amps?
Also you mention hydraulic.....is there a problem with fluid?

 

[jakew009]

No but then there is a stable current over 12v when in use, and when trying to be in use but not working - measured at the wiring going in to the ram so switch and wiring joins etc should not be the problem or I would expect to see a current drop or intermittent current at the unit

I’d still attach a temporary supply from a known good battery direct to the motor as a starting point.

Are there any limit switches?

 

[rogerthebodger]

I have a hydraulic hatch lifter n the stern hatch on my boat which has limit switched ay each end of the stroke.

I the limit switch fails the hydraulic will not operate so check the limit switches and the wiring to the directing valve

If you don't have a direction valve you may have a reversing motor, but you will have reversing relays which are controlled also by limit switches

I also have a screw actuator to raise a hatch which is controlled in a similar way

 

[William_H]

The first question is does the motor make a noise but fails to operate. If so then as said hydraulics etc. Presumably no noise means electrical problem. I would sugest check brushes and commutator on motor in addition to those things mentioned. ol'will

 

[Graham_Wright]

Swap it for an electric one. Cheap and comes with limit switches.