Depthfinder turns off when starting motor?? What can I do

[CrappiesNeyes]

My depthfinder(s)shut off when I start the main motor. Most of the time it is just the one on the counsel but sometimes the bow one shuts off as well. The battery is new. Is there anything I can do to isolate these or any other ideas?

Thanks in advance!

[Jim Almquist]

Do you have a trolling motor battery that you could use as a power source ? Some people get interference on there graphs and others will work fine. In my boat I never have a problem with running my graph off the trolling motor battery and at the end of the day I just plug in my on-board charger to top off the battery.

[SkunkedAgain]

Your new battery sounds like it doesn't have enough cranking amps to both start your motor AND keep your graphs running.

[Pat K]

Your new battery sounds like it doesn't have enough cranking amps to both start your motor AND keep your graphs running.

+1

[Esox_Magnum]

Do you have the starter battery on a charger?? Could be not enough run time on the big motor to keep the battery fully charged.

[Riprap]

Check for a weak ground or poor connection at the battery.

[delcecchi]

This happens sometimes with 500 CCA battery and new suzuki motor. Personal Experience. Not having one of the ground wires hooked up doesn't help either.

[Triple_D]

Had this problem in my boat, the fish finder was installed to the accesory panel. I disconnected it and wired it directly to the starting battery plus installed an inline fuse and problem solved. Use a heavy wire like 12 gauge if this is your problem too.

[walleyemaniac]

Hope I'm understanding your setup correctly. You either need to run a wire directly to your battery or you need to find a terminal that is hot all the time (even with key in off & start position). If your hooked into the ignition side of the wiring system (meaning everything turns on and off with the key) when you turn the key to the start position it kills every circuit but the motor circuits till it's in the run position again. It's enough of a pause to shut most graphs off. This is why your not loosing both graphs all the time, some electronics take a couple of seconds to actually shut down so they will make it thru that breif laps of power.

I think some people don't pay attention to that when hooking up additional electronics. They just find a hot wire and good enough.

You can use a test light and make sure it isn't interupted with the operation of the key in all positions. For example,I've fixed many a aftermarket radio installs for people who can't figure out why the clock on the radio keeps going back to 12:00. It's usually because they don't have their constant feed wire hooked to a direct feed terminal or directly to their battery. So every time they start their vehicle it interupts the circuit the clock operates on and defaults the clock back to midnight.

I don't know about all boats but mine has key operated terminals (ignition feed) and direct feed terminals to hook into. Most cars and trucks are set up this same way.

I'm always a bigger is better guy when it comes to batteries but if your battery is under rated like previously stated that could also be causing you problems. I run alot of stuff off my start battery so I really upsize. I know I have enough capacity for when I'm running my trolling motor or drifting I can keep my graphs, nav & interior lights, radio... going and still start the motor. I wouldn't hook up to your TM battery though, 9 times out of 10 you will end up with interference on your graph. Hope this helps kind of a trial and error deal. To many unknown variables. Would help to know how they're wired in now and what size battery you have.

[Cheers]

We had this discussion a few months ago ! You probably dont have enough cranking amps in your new battery . I went through the same thing when I replaced my battery . I got a bigger battery and the problem was solved . I needed 1000 mca according to my mechanic as it happened I had a spare 900mca battery and tried it and it works . The one I tried to use was only 550 mca