cleaning up 'dirty power' for chartplotter/sonar

Mark Kopyc

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Hey everyone,

Last season I found out that my Garmin GPSMap 942-xs plus connected to a thru-hull transducer wouldn't boot up when it was connected to the house battery
when the engine was running (with the alternator charging the battery). To get me by, I connected it to a dedicated battery (not connected to the alternator).

This year I am adding a Garmin GMR Fantom18 radar and a heading sensor to the system. The boat is also being repowered so the alternator will be swapped out.

Has anyone else experienced problems with electronics like this that are possibly 'dirty power' related, and any suggestions on how to clean things up?
Since I'll be pulling more amps now with the radar I'd really like to connect to the house battery if possible.

I might have a wiring issue, I am unsure. I obviously can't test things until the repower is done..

Thanks a lot !
Mark (Bruno 35 'Panacea', West Bath)
 

Genius

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First step is to measure voltage output from alternator. Also, measure voltage to your Garmin.

Calling it dirty without looking at on an oscilloscope may be jumping the gun.
 

WoundUpMarine

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Mark Kopyc

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Thanks for the inputs. Yes I had a problem whether I was running with the single house battery, the dual starting batteries, and when they were put in parallel. I guess now I'm leaning towards it being a wiring problem.. will troubleshoot and take voltage readings when she's back together, including under load from the electronics. Thanks for the insights. Wish I had an O'scope.. might borrow one if I can't troubleshoot the problem.
 
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Geof Roberts

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Agree, a basic battery set up can be considered as "clean". However what is connected to it maybe causing the problem. I am thinking of equipment using Switched Mode applications, these generate a host of harmonics if not correctly designed.. It is generally known by HF and VHF users that even a common LED lamp can create interference..
 
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