# Insulating electronics from main engine voltage drops



## Surffshr (Dec 28, 2017)

Is there a way to prevent voltage drops when using the trim/tilt or jackplate? Most of it I can live with, but I’ve noticed my radio cutting out badly and not recovering well after adjusting the trim or jackplate. My nav lights dim significantly when making adjustments so i’m attributing the issue to a voltage drop, but I have not actually measured this. I appreciate any input.


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## bryson (Jun 22, 2015)

I know it sounds obvious, but the first thing I'd do is try to rule out any issue with your wiring, such as corroded grounds/connections.

If the system is in good shape and everything is sized appropriately, you may notice some slight dimming of lights, but it shouldn't be anything too significant. It definitely shouldn't cause the radio to cut out badly and have trouble recovering.


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## Guest (Sep 29, 2018)

bryson said:


> I know it sounds obvious, but the first thing I'd do is try to rule out any issue with your wiring, such as corroded grounds/connections.
> 
> If the system is in good shape and everything is sized appropriately, you may notice some slight dimming of lights, but it shouldn't be anything too significant. It definitely shouldn't cause the radio to cut out badly and have trouble recovering.


Well said, correct wire sizing and terminations that are clean and corrosion free are the most important thing in this case! Check your wiring and terminations as stated. If all is good then check the battery condition. If all is still good, a capacitor may be needed for certain electronics but doubt this is your case since you mentioned your nav lights being affected also.


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## Salt of the Water (Feb 26, 2018)

If the cables are all correctly sized and in good shape, maybe the battery just doesn't have the oomph for those large amperage loads. Textbook candidate for a dual battery system with an isolated house battery. Blue sea systems mini add a battery kit will help keep the house isolated from the motor battery when it's pulling large loads, but keep both charged while the motor is turning the alternator. In this case you'd need to put the jackplate on the motor battery instead of the house battery which is a tad unusual but shouldn't hurt anything.

I’d try to do as much of the tilting / jacking as possible with the motor running. Let the alternator do most of the work, and only use the battery for that last little bit, getting the skeg out of the water.


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## Cam (Apr 5, 2017)

If the wiring is solid, you can install a large capacitor between the stereo and battery. That will likely solve the voltage drop when the jackplate or starter is fired up. They are typically used in cars to prevent head light dimming during heavy bass, but should work just as well in a marine setup.


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## WindblownBeard (Aug 1, 2018)

Did you ever get this figured out? I am having similar issues with my new boat. I suspect it may be an underpowered cranking battery for my 50 tohatsu. At idle speeds and low rpms, the radio cuts out and pops. When planed off, there are no issues. I also get cut outs on the GPS and radio when moving the trim tabs .I think the tohatsu may be killing the battery due to the high cranking amps required (850cca)


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## Surffshr (Dec 28, 2017)

I sold the boat.

However, I did replace the cranking battery and ran it a good while before selling. This did help but didn’t eliminate the issue with the radio.


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