Garmin GHC 20 issue

[KenB]

I have a 2020 R27 outboard. Last time out the Garmin GHC20 autopilot would not come on. I could see a faint readout on the screen but it was not illuminated like usual. I got a warning on my VHF radio that no position data had been transmitted for 10 minutes. We anchored out for about 2 hours and headed back. About 15 minutes later it came back on and worked correctly the rest of the way back. I have turned it on several times since and it takes a long time before it lights up. Everything else at the helm appears to be in good working order. Any ideas?

KenB
Cambridge, MD

 

[Bruce Moore]

Bumping post delayed in moderation queue.

 

[SJI Sailor]

I had a similar issue (intermittent display on the autopilot) that turned out to be a loose connection of the power cable. So one place to start would be to disconnect, clean, tighten all the connections there.

 

[Ralf H]

Hi KenB,

SJI is right, check your connections first to ensure all is working properly, especially power. intermittent connections will cause this type of issue. Let us know how it goes from there.

Thanks,

Ralf

 

[Wee Venture]

I have a 2020 R27 outboard. Last time out the Garmin GHC20 autopilot would not come on. I could see a faint readout on the screen but it was not illuminated like usual. I got a warning on my VHF radio that no position data had been transmitted for 10 minutes. We anchored out for about 2 hours and headed back. About 15 minutes later it came back on and worked correctly the rest of the way back. I have turned it on several times since and it takes a long time before it lights up. Everything else at the helm appears to be in good working order. Any ideas?

KenB
Cambridge, MD

A couple thoughts… First, the VHF does not get its position data from the autopilot. As supplied from the factory it comes from the Garmin chartplotter which has its own gps antenna. You can turn the autopilot off with no effect on the VHF but if you turn the chartplotter off, the VHF will start to alarm in 10 or 15 minutes if left on.

Second, if you could see a dim display on the autopilot, it suggests the possibility that the screen brightness got turned down inadvertently rather than simply the unit not coming on at all. This has happened to me. Once you hear the autopilot “beep” as you turn it on, wait several seconds. Then short presses on the power button will toggle the brightness between full, intermediate and minimum. When you can see the screen clearly, you can then set the brightness for whatever percentage you wish. That may not be the issue but maybe worth a try.

John

 

[Dcsqatar]

The lack of GPS data to the VHF sounds like a NEMA 2000 backbone connectivity issue. I would check all the connections to, but particularly between, the Ts in the backbone. If the backbone is not stabilized, I recommend screwing down each plastic T to a board and then mounting the board.