Almost all autopilots supply 12 volts to turn the boat one way and 12 volts with polarity reversed to turn the boat the other way. *Specific to Autohelm/Raymarine wheel drive autopilots*, they have made some modifications to the wheel drive over the years, but the computer does not care about them. They are all about the same amperage and all use 2 wires. I would not go looking for an original AH 4000 unit at this point unless you find one very cheap. They are really old by now and mine has issues with the gaskets and connections I have to mess with every so often. They are close to 30 years old now in 2016. If your drive unit is fine, you can use the old AH4000 computer, an ST4000, or the newer Raymarine wheelpilot computers. I would not try and use some other random kind of autopilot computer. The ones designed for the wheel drives have – IIRC – current limiting and they “know” there isn’t always a sensor to keep it from bumping up against the rudder stop. Honestly the new ones have so much more capability I would be very tempted to get one. I am thinking about it while I fix my 1980s version for the 20th time or so…. Joe Coquina C&C 35 MK I
From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Larry via CnC-List Sent: Tuesday, November 01, 2016 10:46 To: cnc-list@cnc-list.com Cc: Larry <ladoug...@comcast.net> Subject: Re: Stus-List Raymarine ST4000 AutoHelm Joe What I believe you are stating is, all units output on two wires to control a drive unit, like the new electrical rotary drive unit. It is all a function of dc voltage to control the direction of turn. Just as long as the voltage out is the correct voltage and amperage any unit should be able to turn. But then there is the matter of compass input, rudder input and etc. I will check into the AH4000. The ST4000 is a complete unit in itself. I understand they are not all that water tight and are prone to corrosion. There is also a bulletin from Raymarine that suggest soldering a diode across two point. I used to electronics in the Military and including miniature repair (component). I no longer have the eyes, steady hands or tools to do that. I may just take the unit to an electronic repair shop and have them look at it. Assuming all else is functioning as designed. Thanks Larry From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Della Barba, Joe via CnC-List Sent: Tuesday, November 01, 2016 7:31 AM To: 'cnc-list@cnc-list.com' Cc: Della Barba, Joe Subject: Re: Stus-List Raymarine ST4000 AutoHelm If the drive part of your autopilot is good, it will work fine with the older AH4000 as well as the newest Raymarine units. The drive has changed color and detail a bit since the 80s, but they all work the same. One motor that turns one way or the other ;) Joe Coquina Original AH4000 from 1988 or so From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Della Barba, Joe via CnC-List Sent: Tuesday, November 01, 2016 10:09 To: 'cnc-list@cnc-list.com' <cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> Cc: Della Barba, Joe <joe.della.ba...@ssa.gov<mailto:joe.della.ba...@ssa.gov>> Subject: Re: Stus-List Raymarine ST4000 AutoHelm The drive is a 12 volt motor with two wires. Connect it directly to 12 volts and the helm turns one way. Reverse the wires and it turns the other way. Do that first and also REALLY check the power supply. I have gone nuts with bad connections that dropped the voltage when the drive motor turns and even worse, you can have an issue where the main power connection is bad and the autopilot is running off the +12 line on the Seatalk bus. That cannot support actually running the drive motor. Joe Coquina C&C 35 MK I From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Larry via CnC-List Sent: Tuesday, November 01, 2016 09:39 To: cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com> Cc: Larry <ladoug...@comcast.net<mailto:ladoug...@comcast.net>> Subject: Stus-List Raymarine ST4000 AutoHelm I am in the middle of troubleshooting my auto pilot, but I believe it is a lost cause. The boat is relatively new to me. I have owned it just two seasons. I spent the first season just taking her out occasionally and going through her, cleaning, repairing and replacing items that did not meet my satisfaction. This season I took her out and enjoyed the season. I have always left the st4000 in standby and it seemed to work fine. Then I decided to check out the st4000 out completely and ran into errors. It appears to be fine at first in the Auto mode, until I try to actually use it. It does not actually do anything and within 5 min the display will read “low Battery” and occasionally “no Data”. I checked the voltage to the Unit and it is good. I know I have a little more work to do. Like actually check the drive unit and see if it works at all. I can purchase a control head for 500 dollars on eBay. But I need to determine if anything else is bad first. Has anyone else replace the auto pilot system on their CnC and if so with what. Larry 1986 CnC 38-ft MKIII Freeland, WA
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