View Full Version : Lowrance lms 480
I have put one on the front of my boat and when I turn my trolling motor up over 25 % in water 10 ft. or deeper I get black bars going vertical on the sonar screen is there anyway to get rid of this or do you guy's have the same problem?
perchjerker
08-17-2004, 03:17 PM
Are you using your trolling motor battery to power up your sonar? If you are it could be causing interference.
I have that problem also. I have a 24v Minkota hooked up to 2 separate batterys in the front of the boat. I have my GPS and Lowrance 350 hooked up to a battery in the back. Also have a starting (only) battery in the back. I get those big black vertical lines on my 350 when I use my trolling motor. If I keep the sensitivity down around 50-56%, it is ok. But if I try to go higher on the sensitivity the lines come back. I have a autopilot and co-pilot and tried using the trolling motor without any of that and it still does it.
Yes I have a 24 volt trolling motor and the sonar is wired to one of the batteries up front, but if it was interferance from being hooked to the same battery would'nt it have black lines when trolling motor is running on 25% power level also.
Yes I have a 24 volt trolling motor and the sonar is wired to one of the batteries up front, but if it was interferance from being hooked to the same battery would'nt it have black lines when trolling motor is running on 25% power level also.
Eye_Guy
08-19-2004, 06:22 PM
I had the same problem with my X-135. I now hook up one battery to my X-135 and one to my trolling motor and gps. I have no problems now! When I lowered my sensitivity I hardly marked any fish so don't lower your sensitivy to make the screen more clear. Run sepaerate batteries.
Stephen Sherk Jr.
Northern Eye
08-22-2004, 09:33 AM
I had the smae problem with my Eagle 480. I have been in contact with minnkota about this problem. I have a 74APUS and could not mark fish and experienced the same black lines. The sonar is run off the starter battery. The problem is the maximizer in the trolling motor is emitting interference through the transducer. I tried grounding the trolling motor batteries to the starter battery (as suggested by minnkota) this did not solve my problem. I then tried grounding the trolling motor housing to the common ground and this fixed my problem about (90%). There is still a bit of interference but I can mark fish and read my grayline. But now I have a wire running from the motor housing to the ground of my boat.
I asked Minnkota if they were aware of this problem and they indicated that it can happen with some sounders, although most of my fishing buddies are experiencing the same problem (sounds like a design flaw). They suggested that I send the motor to a service depot and had the motor gouunded. I would like them fix it for me and pay the shipping as I live in Northern Ontario. I will let you know how I make out.
Minnkota.
I agree with you. We would recommend routing the wire internally. We would recommend attaching the wire to one of the brush plate mounting screws in the lower unit, run the wire up the I.D. of the shaft and the connect it to the brown wire in the control box of the 74 PDAP motor. You will accomplish the same result, and the wire would be on the inside of the motor.
My response
How do I route the wire internally? I do not feel comfortable about taking apart a motor that I just purchased in the spring.
I'm curious, if this is a known problem then why is the grounding not completed from when the unit's are assembled?
Minnkota
I would not recommend you do this either. I would recommend that you have either a service center near you do it, or send it into us to have it done. The issue you are experiencing is not considered a problem with the motor itself. The motor operates to its factory specifications. The interference issue comes about randomly on motors with the maximizer system built into it, and is unpredictable. The depth finder just happens to operate on a frequency that a harmonic of the maximizer system interferes with. It is not considered a defect in the motor.
Pitts
08-22-2004, 01:33 PM
I have a Motorguide Excel 71# 24 volt that I have an X-85 on and I get black lines if I turn up the sensitivity above 50% with this system.
I still see good marks for fish and the black lines are only there when starting operation not continuous unless I turn it above 75%.
Your not alone
Pitts
Northern Eye
08-23-2004, 03:11 PM
Well, I got my reply from Minnkota and they indicated I'm on my own to have the motor housing grounded in order to clear up my interference problem. I have to get a quote from a local shop but, I still think this should be covered by Minnkota. I will check the cost then call their customer service department. I think this is a flaw in their design and the consumer should not be paying for it.
Brian Herring SC
09-08-2004, 04:06 PM
Hey this is a southern fisherman. I just bought a lil bass tracker panfish boat. I turned the live well into a tank for my bait. I striper fish, and thats what the boat will be used for. Now I need a good depth finder and friends have told me about the Eagle Fish Elite, Lowrance X135, and Garmin 240 Blue. Well anyhow if any of ya'll can help then e-mail me at CoachBFishing@aol.com God Bless, Brian