Muir Winch Quits

[RickB]

... the motor has 3 terminals-up/down/negative ... we checked for power at all points from footswitch to winch. We get 13.5v all the way to the 2 cable ends which bolt to the the winch terminals. But bolt them on and test, we get no power reading at all.

Are you saying you are using a meter and get a voltage reading at the motor terminal end of the positive and negative cables with the cables disconnected from the motor? Is this voltage present even when the foot switch is not closed by stepping on it?

Does the voltage reading drop to zero when the leads are connected to the motor but the foot switch is not closed?

Try placing a 12V light bulb between the terminals on the motor and see if it lights up when the switch is closed. Try the same test with the light bulb between the wires when they are disconnected from the motor.

It really does sound like your foot switch is bad. A digital voltmeter will indicate voltage even when the switch has far too much resistance to conduct any useful amount of current. If you are reading voltage without a foot on the switch, that shows the switch is faulty and is leaking a small amount of current ... probably soaking wet inside with seawater.

As soon as you connect the wires to the motor, the motor presents a low(er) resistance and you get no voltage reading. If you don't get any voltage at the connected terminals with the foot switch closed, it's the switch.

Take a battery and jumper cables to the bow and connect to the motor terminals (wires off - don't touch threaded stud directly, connect to nuts only or you will damage the threads) if it works then, it proves the switch is the culprit.

 

[BruceK]

Thanks Peter and Rick for responding. We brought the winch home, just tested it on the car battery, and it runs.
We are testing with a meter. We get power at the cable ends unconnected, but connected, switch operated, nothing. The winch working led us to suspect the switch of failing under load or intermittently too. I don`t think we tested for power, cables connected, switch not operated.
I bent (because of how I thought I`d need to fit it) and unbent the lugs on end of the -cable connecting the winch, it seems too flexible at the lugs so I`ll replace it. If nothing changes I`ll replace the switch. I could not trace the earth cable attachment point, I will try that again.
I will leave wiring it to the helm for now, under pressure to get us mobile for NYE fireworks, we need a functioning winch for anchoring in around 20M of water amongst numerous boats.

 

[BruceK]

We changed the foot switch, and all is good. It is well bedded in Sikaflex. This winch motor runs much faster than the old one, I`m sure we had both motor and switch issues, old age probably in both cases. Thank you all very much for your help, especially RickB with the diagnostic steps. We can now think about the Sydney NYE fireworks.