andyp
Well-Known Member
Advice please,
My 40ft yacht has a Simrad Robertson Autopilot setup with a J300X central unit controlled by an AP20 at the wheel and a linear drive unit linked to the rudder quadrant.
All was fine for a year, but this season the clutch has permanently engaged as soon as the J300X is powered up from the AP20. The steering wheel then locks, even though the AP20 may be in Standby and manual control of steering can only be achieved by powering the J300X off using the AP20 or tripping the circuit breaker.
On investigating, I measured a permanent 12V on the Clutch Bypass connections, this then feeds via a simple car relay to the linear drive unit. I have temporarily fitted a Maplin/Velleman wireless remote control relay between the J300X and the car relay which interrupts this permanent 12V signal and allows me to steer manually when needed.
Does anybody know the likely cause of the permanent 12V on the J300X Clutch Bypass connections? Will it be an easy one to find - blown capacitor or track shorted out? Would a swap of EPROM chip from another J300X cure this fault? Or will my temporary fix become the permanent fix until I can afford a complete new autopilot system? I am loathe to replace as it handles the steering, including wind vane steering very well.
My 40ft yacht has a Simrad Robertson Autopilot setup with a J300X central unit controlled by an AP20 at the wheel and a linear drive unit linked to the rudder quadrant.
All was fine for a year, but this season the clutch has permanently engaged as soon as the J300X is powered up from the AP20. The steering wheel then locks, even though the AP20 may be in Standby and manual control of steering can only be achieved by powering the J300X off using the AP20 or tripping the circuit breaker.
On investigating, I measured a permanent 12V on the Clutch Bypass connections, this then feeds via a simple car relay to the linear drive unit. I have temporarily fitted a Maplin/Velleman wireless remote control relay between the J300X and the car relay which interrupts this permanent 12V signal and allows me to steer manually when needed.
Does anybody know the likely cause of the permanent 12V on the J300X Clutch Bypass connections? Will it be an easy one to find - blown capacitor or track shorted out? Would a swap of EPROM chip from another J300X cure this fault? Or will my temporary fix become the permanent fix until I can afford a complete new autopilot system? I am loathe to replace as it handles the steering, including wind vane steering very well.
