Graph shuts off when starting motor

[WalleyeWarrior]

Nearly every time I start my motor the graph kicks out. I believe this may have to do with the draw down that the battery experiences when starting, but this is extremely frustrating. Usually it takes a few minutes before I am able to turn the graph back on. Am I correct in my belief? If so, is there any way to fix this? My starting battery is only a couple years old and the voltage seems fine when I put the tester to it.. If I'm wrong in my thoughts, any other ideas? Thanks in advance for the help.

[whitebassman]

maybe you need a battery with a larger cranking capacity? What is the cranking capacity of the battery and what is the draw from the motor when cranking?

[Ed Carlson]

Many graphs will shut down at 10V, so it's a voltage drop from the cranking draw. Watch the voltage on the display and see if it spikes down to below 10V just before it shuts down at start up.

Check all graph connections and the fuse holder connections well, for corrosion and tension at the fuse...even change the fuse. Low voltage may be a result of a weak link so start there. This is a common issue, especially at the fuse.

After that if it still persists you will need to look to the battery as a possible need to be replaced or upgraded to a higher capacity model. Another good option is to add a second battery on the accessory line. We did this on our boat and now we never worry about draw down or running out of juice on the accessory banks.

[Tator2k]

Same thing happened with my new HB. In my case I'm pretty sure it's the battery.

[Cheers]

I went through the same thing last year and solved it last week . My mechanic pegged it right away . The voltage draw when the motor is starting is greater than the batteries ability to react so the finder kicks off on low voltage. For my motor ( 130 Opti max ) he said I should have 1000mca battery ( mine was only 650 ) . He also said to throw away the wing nuts and replace them with stainless steel lock nuts and tighten them up well. He also recommended cleaning the terminals and greasing them with dielectric grease or Vaseline . I followed his direction and it worked. Just as a test I tried running live well pump, 2 fish finders and raising the trim at the same time as cranking the motor and it all worked

[Deitz Dittrich]

I will echo the above post.. take some sand paper to each of the connectors, clean them up really good.. make sure the terminals are tight.. if that doesnt work, time for a bigger better battery.

[Ed Carlson]

With the modern demands we put on the accessory line and the starter circuit, the 1000mca is the smart choice right off the bat.

Never going to cuss about too much reserve power, but you will if you have too little. The added cost is nominal for the security it provides in the long run.

[Maverick]

I had the same problem with my GPS. Turned out to be a bad ground under the dashboard of the boat. I run a Lowrance graph and a gps. They both give me a readout of the volts. The GPS was consitantly 2 to 3 volts less than the graph, so I knew it wasn't the battery. After completely rewiring using new connectors I solved the problem. Good advise on the fuse Ed. The old glass fuses especially seem to lose contact over the winter. I always have to clean them up in the spring.

[Ed Carlson]

The spring tension on the glass fuses often gets weakened...so I slip them out, clean them up of any carrosion....and stretch the spring on both ends so the contact pressure increases.

If they heat up after a short, the spring will often lose it's temper and fuse contact suffers resulting in a voltage drop across the fuse.

[SkunkedAgain]

Dielectric grease is great for keeping corrosion out of marine connections.

[WalleyeWarrior]

Thanks for the input guys. I've got a 115HP Johnson and I know my current battery doesn't have enough CCA. The best that I can do locally for this is 885CCA, but I believe this is probably about 200CCA more than my current battery. I'm also going use the dielectric grease and SS locknuts as well as take a look at the fuse holder.

On a side note, how are the Minnkota 3-bank chargers? I'm tired of charging one battery at a time and want to bite the bullet and invest in an onboard charger.

As always, thanks for the all the help and input.

[MuskieJunkie]

On a side note, how are the Minnkota 3-bank chargers? I'm tired of charging one battery at a time and want to bite the bullet and invest in an onboard charger.

You might be better off starting a new thread for this in the Boats section.

I've never used the Minnkota brand but on board chargers in general are great. Takes the guess work out of charging and it's a lot more convienent. When you install one I would recomend putting the 110v plug in a spot on the boat that you can reach from outside the boat so you don't have climb inside to plug and unplug.

[eyebjim]

The problem is likely the voltage drop from the battery to your fuse box (the wire) not from the battery itself. Running a separate wires to power the graph directly from the battery will likely solve your problem. I had the same problem and it was solved by doing this.

[spearchucker]

The problem is likely the voltage drop from the battery to your fuse box (the wire) not from the battery itself. Running a separate wires to power the graph directly from the battery will likely solve your problem. I had the same problem and it was solved by doing this.

Could be as simple as cleaning the battery connections too. Dirty connections will cause more voltage drop when cranking.

[Wilderness55]

I have a similar problem. However, only one of my GPS units turns off?

My front locator works great when I am using the trolling motor, however, when I pull the troll and head back to start my motor, it shuts off. My counsel locator remains on and seems to be working great. Any advice would be great? Thanks!

[Ed Carlson]

It your case.. it may be wired to the accessory power circuit.

Then when you cycle the ignition to start, it drops the power to the unit just low enough and long enough to power it down? Best guess anyhow?

If you power it off a 12 V front battery, away from the accessory circuit line, it should remain on. But you will need to remember to shut it down at the end of the day to insure it does not draw power when not used.

[osok]

Are you running this directly to the battery or through a panel/switch and ground plate? Definitely check ALL your connections, especially the ground (so often overlooked). Clean all your contact points to metal to metal (wire brush or fine emery cloth) and absolutely use either dielectric compound or vasaline before reassembly.

[Juan Grande]

I have a similar problem in that my graph shuts off when I start my motor and it won't read bottom (the depth flashes and wont' change as I'm moving). My starter battery died while on the water last week so I hooked up one of my deep cycles to start the motor. The fishfinder is also hooked up to the starter battery and ran like a charm with the deep cycle. My starter battery is 5 years old and I think I think a battery with higher cranking amps. What's a good place to buy higher end batteries in the metro?

On a side note, I bought my boat at Rapid Sports Marine and they hooked the fish finder up to the starter battery and not the deep cycles. Not sure why. Is it tough to rerun the wire?

[SpecialK]

Juan your starter battery is in need of replacement which you already know. Gander, Big C and any boat seller will have the batteries you are looking for.

You want your graph hooked up the starting battery not the trolling motor battery. The trolling motor can cause interference on your graph not to mention that typically that battery gets drained down lower than the starting battery on a normal fishing trip which will cause the same symptoms you have now.

Replace the starting battery and call it good.

Good luck

[Juan Grande]

Thanks Special K. What specs should I get on the starter battery? I have a Merc 115 horse 4 stroke and a Lowrance 332C running off of it.

[SpecialK]

Everything I know about it is to get a Marine Starting battery with the highest CCA (cold cranking amps) that you can find. I am not familiar enough with all the different batteries out there to tell you what that number is. If you go to Gander or Big C the people on the floor should be able to point you towards the right battery.

[Ed Carlson]

Go with at least 1000 CCA, don't go under that or you will regret it latter. A duel purpose battery with 1000CCA will also have a higher Reserve Capacity rating, important for longevity of accessory load management. If you run a lot of toys and the live well, this is important to look at.

A Blue Top Optima D27M or an Interstate 27M-XHD class will serve you well here. The Blue Top sports 1000CCA and 140RC and the Interstate 27M-XHD sports 1000CCA and 180RC ratings, ideal for big motors and lots of electronics on board.

[SpecialK]

I knew one of the smart guys would chime iin and give the particulars eventually. Thanks for bailing me out Ed