Autohelm 4000+ trouble

[Kobi Maru]

My Raytheon ST4000 Plus autopilot will no longer steer to the port side. It is mounted on a 1999 Hunter 340 sailboat. It seemed to be having trouble for the last several outings, but now will not hold a course. It steers to the starboard ok. All the electronics seem fine. I suspect it has something to do with the mechanical drive, but I have no idea how to investigate. Any ideas?

 

[Ken]

Autohelm

It's likely the plastic gears are broken, it should run you $100-$150 to repair. Just be glad you weren't crossing a large water body or rough seas depending on those plastic gears.

 

[Walt]

Check the drive belt

The Autohelm 4000 wheel autopilot on my boat developed similar problems, which were caused by a worn drive belt. The motor/drive unit will pop apart at the seam (along the circumference of the wheel) if you apply some pressure with a flat tool like a large screwdriver. At least mine did - just be gentle about it. You'll then be able to see the belt and drive gear. In my case some of the cogs on the belt were worn, causing slippage.