Problems with newly installed Garmin 93SV on Trolling Motor- vibration or interferenc

[KevinH-BCB]

Justin - glad to hear that you are having some success. I am like you, with the MG Digital Tour. I checked to see if there was any resistance between the starter battery and the trolling batteries, thinking that if it was none, then the charger would not effect me. Did you ohm out between the two battery systems before you disconnected the on board charger? I've heard of people installing a switch between the on board charger and main starter battery.
I have the ferrite magnets installed on the transducer and power wires to my Garmin unit. They made no difference to mine. I will try disconnecting the battery charger next. I've run out of options at this point. I did install some foam between the transducer and transducer clamp with no change this past weekend. When I turn my unit on, I have to adjust the gain manually down to less than 50%, and pending on the speed setting of my trolling motor, sometimes even less. It sucks!

Well I had a small breakthrough today for any keeping up with this. I realized I hadn't tried unhooking the charger. Got on the water pulled the fuses going to each leg of the battery from my charger effectively disconnecting it completely and eureka!!! It didn't completely remove but it made it MUCH better. Before I couldn't manually adjust the gain on 2d past 49 and it would start introducing interference. Now it will go to 65 before it start showing interference and the actual amount showing is way less. Just a quick small line then mostly gone. Before it was a huge band that would stay for 3-4 seconds. It also completely cleared the downview. Before if I would stay on the trolling motor the downview picture would completely disappear. I already have a few different ferrite cones and rings on the way and I'm going to go ahead and try to get rid of the last bit but today was defiantly a broke through.

[Larry3215]

you mean to tell me you effectively disconnected the on board charger and it helped your interference? where do you have your garmin power wires going to? cranking battery?

I thought might try this but I have a dedicated alone battery for my garmins so im not sure the onboard charger could affect them all..

The (sometimes) problem with - some - on-board chargers is that they connect all the grounds together on the batteries they are hooked up to. That - sometimes - helps with interference and - sometimes - makes it worse.

No way to tell until you try it both ways.

[Larry3215]

It doesnt have to be a direct electrical connection. Some on-board chargers have circuitry/board setups that allows the interference signal to get transferred across by inductance/capacitance transfer = no resistance with a meter.

You cant really tell except by trying it both ways.

[KevinH-BCB]

I have run a temporary ground wire with a in line fuse from the trolling batteries and the starter battery. It did not help me in my case. I will try disconnecting the charger to the starter battery and see if that makes a difference. Thanks Larry

It doesnt have to be a direct electrical connection. Some on-board chargers have circuitry/board setups that allows the interference signal to get transferred across by inductance/capacitance transfer = no resistance with a meter.

You cant really tell except by trying it both ways.

[11justin22]

Kevin no I didn't ohm between them. I have a minn kota charger that has fuses on each leg, just quickly pulled then on the water and it worked. Now there's still some but it's heaps better.

Louivieto- yes connected to the cranking battery. Charger is hooked to cranking and both trolling batteries.

[louievito]

I see now...that makes sense. should have known better that all the batteries go through the onboard (cranking, tm) im in a state of mass info gathering and sorting in my head. I might try that this weekend to see if helps the interference on my number 5 tm speed. that's the only speed it does it on and there is no electrical interaction from tm to unit since I have a dedicated battery, grounded skeg, and wires away from tm. only thing that connects tm and cranking battery is the onboard. good luck sounds like your getting close

[Carolina_Rig]

I've been following this thread for some time to see how it progresses. I also have interference with the graph at the bow and I'm undergoing similar steps to resolve. Here's where I'm at. Garmin Echomap chirp 93SV at the helm and Lowrance Hook 9 at the bow. Terrible interference at the bow graph. Skeg was already grounded back to 24V ground, and this worked for the Raymarine I was previously using. Not for the Hook unit. Then I tried grounding skeg to the 12V side, as well as no skeg ground at all. No ground was worst, 12V ground was best, but completely unacceptable.

The last test was snipping all the zip ties from the TM shaft and removing the transducer. I put the TM in the water and about 5 feet to the side of the boat I held the transducer under water and bumped the TM. All the interference was there.

I work in industrial automation, so I scabbed about 30-feet of shielded VFD cable from the controls engineer at work and ran that from cranking battery to up to the graph up front. I also installed a speed plug between cranking battery and charger, so I can make a clean break while fishing. Finally, I installed an RF choke at the power connection to the graph. I haven't had a chance to test this out on the water, and if it works I probably won't know which approach worked, since I may be killing a gnat with a sledge hammer.

I'll report back after a lake test.

[KevinH-BCB]

Latest Update: I took the rig out yesterday. I disconnected the on board battery charger before I hit the lake. This did not make a difference in my case. I'm stuck at this point of anything else to try, other than replace the new trolling motor. This is what I have done all together with limited success:
- had local shop install an internal ground in the TM
- Added ferrite magnets to both the transducer cable and power cable.
- I have added aluminum tape to the transducer cable for shielding, then taped it with electrical tape, and put spiral wrap on that to help separate the cable from the motor.
- I have removed the excess transducer cable from inside the boat to ensure that it is way away from the power and ground for the trolling motor. I have coiled it. I have formed it into a larger coil and then twisted it into a figure 8 and then folded it onto itself. I have serpentined it as well.
- I verified that the trolling motor power and ground is run along the keel, away from everything else.
- I have shielded the back side of the trolling motor plug with electrical tape and then aluminum tape.
- I have run separate new dedicated power and ground wires directly from the starter motor to the Garmin unit.
- I have disconnected the charger from the starter battery
- I have updated the software in the unit
- I have temporarily installed another Garmin 93SV unit and still got interference from the trolling motor when activated.
I still get interference from the trolling motor when activated. I have to turn down the Gain manually to 55% or less to eliminate the interference. I have tried different frequencies, and Auto Low, Med. & High Gain settings.
I do not what else I can try other then replace the trolling motor, which is a big expense I can't handle right now on a new rig.

[Larry3215]

Sounds to me like you have tried all the usual options.

Did you try connecting a wire from the ground on the starter battery to the ground of the trolling motor battery? Sometimes it help to have them connected and sometimes just the opposite.

Where did you put the chokes? The one on the TM needs to be as close to the head as possible - not the battery end.

The choke for the Garmin needs to be as close to the Garmin as possible. I would also try a choke on the Garmin power leads.

Thats about all I can think of.

[KevinH-BCB]

Larry - I did try the ground between the starter and TM batteries - no luck. Bass Cat Boats stated that they have found that this created a lot of issues with their rigs and strongly advised against it.
I have chokes on both the PWR lead and transducer on the Garmin at the head unit. I tried chokes on the TM at the plug - no change. I have also had a local repair shop install an internal ground in the TM too - forgot that in my list.

[Larry3215]

Sounds like you have tried every thing then.

There is a remote chance moving or adding a choke as close to the head of the tm as possible may help. Im not real hopeful though. Depends how far away the plug is from the head.

[KevinH-BCB]

There is no good place to put a choke on the outside of the trolling motor, but you got me thinking that I may be able to sneak one or two inside the head cover. I'll pull the cover and see - thanks Larry!

Sounds like you have tried every thing then.

There is a remote chance moving or adding a choke as close to the head of the tm as possible may help. Im not real hopeful though. Depends how far away the plug is from the head.

[TroyBoy30]

have you tried the tmc1?

http://www.humminbird.com/Products/TMC-1/

[KevinH-BCB]

have you tried the tmc1?

http://www.humminbird.com/Products/TMC-1/

Troy - where is this installed?

[Larry3215]

There is an installation guide on that page. I think it goes inside the head.

[LWINCHESTER2]

Once upon a time..... I installed it just behind the power plug of the trolling motor. The kit I got from Hbird had more than this. Also had some chokes. That could have been thrown in by Customer Service. What I received may have been the kit plus chokes. Maybe 8 years ago. It did help. And the ground wire to the skeg helped. Didn't cure it though.

Now I have 6 transducer cables that run the full length of the trolling motor and wound around the cable back to the pedal. The power for the Blue Seas fuse box runs parallel with and beside of the power cable for the trolling motor. Also power to 2 units at the back of the boat from the Blue Seas there as well as more transducer cables. All the wrong things to do. No interference. Before I got rid of the Maxxum and put the Edge 70 on I had interference everywhere. Then Lowrance HDS, Hbird, Vexilar. Now - nowhere with Garmin, Lowrance, Vexilar.

[TroyBoy30]

Troy - where is this installed?

as close to the foot pedal as possible. mine is not in the recess. it's further away inside the gunnel

[cactusflyr]

I got my transducers away from my trolling motor housing with this.....had it fabricated myself. Also. On your rf chokes and such....can't go cheap here. There are countless beads and chokes that you can buy....but they do not usually target the frequency range you are trying to fix. You want a 1) W material choke or bead....best. 2) 75 material..good, 77 material...good. Try here..https://www.amidoncorp.com

http://www.bbcboards.net/showthread.php?t=790453

[cactusflyr]

http://www.amidoncorp.com/w-material-ferrite-toroids/

note the frequency range it targets.....most target much higher frequencies.

[Larry3215]

Excellent tips! Makes me wonder what the Humminbird ones are made of.