Hi folks, a friend of mine has a Minn Kota Ulterra and every time he runs the spot lock on it and it would interferes with the HB 597c so bad you couldn't read or see the graph. The ground wire to the trolling motor is good. He didn't have the issue when he had the motorguide. What is causing the problem? Any suggestions ? Thanks in advance.

Bump

He needs to be sure the power cable for the 597 is attached to the starting battery both + and -. This should resolve all interference.

If you aren't able to figure it out yourself Lake Fork Electronics will be glad to help.

Use 10gauge stranded twisted pair directly connected to the crank battery.

You did not clarify if the problem only happens when the motor actually runs, or if it happens constantly once spot lock is turned on. Which is it?

Is the TM power system completely isolated from the 597? In other words, do not run the 597 with power from a TM battery, and do not connect the Ground for the 597 (or boat battery) to the TM power Ground terminal. Please clarify this, and correct the connections if any of this is true.

If none of the above is true, then the interference is getting to the 897 via airwave emission of electrical noise. At that point, the twisted pair would be the thing to do. There are technical reasons why the twisted pair power wire can help with air-coupled electrical noise that we don't need to discuss here. There is no technical reason that 10 gauge is required as suggested by another post. 12 ga. wire will provide more than enough power for a 597 with virtually no voltage drop (and save some money). If you run new wiring for power, it is absolutely necessary to put an inline fuse at the battery end of the wiring. WIthout that, a short in the wire in the future could send the boat up in smoke.

To make twisted pair: Unspool two long pieces of wire (red and black), a good bit longer than the route the wire will be taking because twisting will shorten it up quite a bit. Put two ends in a variable speed drill set on the low-speed range. Have someone hold the other ends off the ground, separated. The number of inches per twist will be determined by how close the ends are held together at the far end. Run the drill slowly to twist them together evenly, with the goal being one twist about every 3 inches. (Two inches doesn't hurt, but uses more wire, just fyi.) Don't worry about part not twisted for getting the battery terminal connections. You no longer need a fuse at the 897 power cable near the unit as it is redundant if you follow directions and put a fuse at the battery. This protects all the wire and keeps the number of connections low.