We have started having a problem with the original Autohelm ST7000 autopilot fitted to our 1991 Santorin. When sailing along it will just stop working without any warning until such time as it veers sufficiently off course to trigger the OFF COURSE warning. Hitting Standby and turning the boat back onto the original course and then pressing Auto will restore it for a time before the problem returns an hour or so later. No other error messages come up on the display.

I know this is an old unit but we would like to keep it in good working order as a backup to our recently installed Raymarine X30 Smartpilot which incidently we are very pleased with.

Any ideas or suggestions welcome.

Maurice & Heather
SY Baracca
New Zealand
Santorin #41

Maurice & Heather,

Your problem sounds to me like you have a failing clutch in the drive unit. When these Raymarine clutches begin to fail they will let go after working file for hours. As the failing clutch slips, the autopilot and clutch work harder, increasing the heat of the clutch and the drive unit...and it fails and off course you go. The 7000 head unit should give an alarm at this point.

The clutch can be replaced (not rebuilt). Raymarine or a Raymarine dealer can do this for you, or you can order the clutch and give it a go.

Remember the clutch is always 12 volts. Most Raymarine computers have either a switch that selects 12 or 24 volts for the clutch, or the later models have a clutch fuse that is inserted into either the 12v or the 24v slot. Unfortunately, if you select 24 volts for the clutch at the computer, the fuse will not blow, and the clutch will work for up to 200 hours at 24 volts before becoming toast.

Hope this helps your situation.

Regards,

Bill, s/v BeBe, SM2k, #387
Currently Langkawi, Malaysia
Blog: http://www.svbebe.com