My simrad autopilot with RC42 rate compass is connected to my E120 RM. Returning from the Bahamas my autopilot compass was not aligned with my mag compass and was off approximately 90 degrees. Sometimes it would let me set auto on the pilot with the heading off 90 degrees and it would hold the course I was headed. Other times the ap compass starting turning and it would not hold a course. The heading shown on the RM is the same heading that is shown on the AP control. The ship on the plotter is turned 90 degrees even if you are heading in the correct direction and on a straight line. Any ideas is this a rate compass issue? Can it be rebooted?
It is most likely an issue in your settings. It lost your seatrial preset. The compass (for the autopilot), can be installed at any number of directions where it mounts. Then in the settings menu you would adjust the offset (in your case about 90 degrees) and save it. Or if it does the seatrial setup, it might adjust itself. It sounds to me that it lost this setting. I just had this happen out of the blue on a Furuno navnet radar and all of a sudden 1 day it was about 180 degrees off.
Have you installed or serviced anything within 5 feet of the AP compass lately? Would you have a motor or pump that is running that usually did not? New spares or tools on board? Go out and spin the boat and do the install AP compass setup and run the rudder self program. You will need some calm wide open water (real calm off shore day) since the ditch around your area does not offer the room. I have the same AP25/26 system and every 2 years it needs a new base reset (install setup). I keep adding junk, tools and spares to my boat..... Bless it's heart, amazing it does so well on Josea. I could never go to another AP. I also cheat. The boat came with a constant running pump that works like a champ.
Speaking of which. We had one that every once in a while the autopilot would do real screwy stuff like turn the boat 30 degrees while at 32 knots (2004 54' Hatt SF), turns out they mounted the compass about a 1' above the hot water heater in the engine room and when the hot water heater cycled on, it made the autopilot do screwy stuff. Took a while to figure that one out, because it would mostly work fine. Being that Skips is 90 degrees off, leads me to believe it lost it's base setup settings in the installation.
It's aqua space, always changing and a challenge. Good bug Skippy J. Good find. Good input. It's these things that remind us it's a living boat. Yep, sudden 90 off, something has changed and the base line setup should be run. If the compass can not handle any new environment it will error. A starting battery issue (same bank over current) could cause the AC10 (20) box to loose it's setup also.
No changes have been made to anything. Thanks guys will try to do an AP reset. Assume the process is in the manual. Thanks
You might also try calling the Simrad tech support 800 number. I have all Simrad electronics and have called them several times and they are very helpful. Sorry, don't have the number in front of me but it is in the manual.
Capt J, Was thinking about the issue. If the reading on my E120 was the same as the reading on the AP autopilot head wouldn't that mean the RC42 might be the problem. I believe the AP gets its heading from the E120 chartplotter. Or is it the other way around. I know on the chartplotter it showed the ship always 90degrees to the direction line we were headed. Thanks, Skip
Yes, the issue is probably on the chartplotter side. You will have to go into it's setup menu and determine how to change it.
I installed an autopilot that was giving me fits. The compass was mounted a long ways away from anything that should affect it. Took it out for a sea trial, compensated the compass, aligned the heading and everything was great. I got back to the dock, cleaned up all my carnage and checked it one more time. The heading was now out almost 90 degrees. Took it back out on the water, did the whole compensate and align heading process again. All was good. He called me up a couple of days later and said that the heading was out almost 90 degrees. I replaced the compass and did the whole compensate, align once more. Got back to the dock, tidied up and checked it again. Its now out 90 degrees the other way. Absolutely nothing had changed on the boat,,,,,,,,,,,,except that I had closed the companionway door. When they built the boat they had embedded a rare earth magnet in the door and the bulkhead to hold the door open. The magnets were covered in laminate and invisible except to the compass. As I opened and closed the door the compass would swing back and forth. I moved the compass about 6 feet away from the door and no more issues.
The AP25/26 will use it's compass thru the AC10 (20). Unless there is a failure then it may (user setting) use a NMEA compass. If you overlay your radar over the charts on your E120, then you have a RayMarine compass somewhere also. Your GPS should show you course made good. Is it close to the mag compass or the AP compass. So, 2 electronic, one mag and course made good from your gps. Witch one is in error? Or witch ones match? Your cell phone, hand held or cig lighter laying over the Ray compass or next to the mag compass? Is your display showing heads up or north/course up?
Been out of town and returned this weekend. Went out in the boat and problem has corrected itself. How I don't know but autopilot and rate compass heading are correct and shown correctly on the chartplotter.
Sounds like you either had something metallic near the compass, some other form of electronic interfering with it, or the compass is starting to go bad.
There isn't anything metallic close to compass. It has always been mounted in the ceiling area above the master bed on the forward wall. Could be its going bad.