Problems with ControlKing speed control on 9.9hp merc

Trueblue3

Recruit
Joined
Feb 28, 2015
Messages
2
I have a ControlKing speed control on my 9.9 merc bigfoot to fine adjust trolling speed. I also have a Remote Troll steering control on the same motor. The speed control works fine until I use the remote troll toggle switch to adjust steering. Seems there is a voltage spike that causes the ControlKing servo (mtd on the motor) to change speed. I have contacted the ControlKing folks and they deny any problems with this. The wires to both the ControlKing and remote troll servos are close together, and can't be relocated. Here is what I have done so far to try to fix the problem:
1) I took the ControlKing off the main batteries and connected it to a separate 12V 9ah rechargeable battery. This worked but its a nuisance to worry with recharging the smaller battery, especially on longer fishing trips.
2) I replaced the 9ah battery with a 12v to 12v isolated dc power supply rated 15 watts. This worked fairly well until summer when the weather got hot. The powersupply seemed to just shut down a couple of times.

Has anyone had this same problem and how did you fix it ?

3) I'm currently thinking about eliminating the remote troll steering servo and replacing it with a main motor to trolling motor tie bar. This would forfeit some of the flexibility of steering the trolling motor, but it would at least eliminate the voltage surges to the ControlKing (I think). The downrigger motors might be a problem as well. Would appreciate any advice you might have before I make another change.

Many thanks, Trueblue3
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,582
:welcome: to iboats

Haven't had any dealings with the model nor be able to find much about the controller. Sounds like maybe there is some interference with other circuits, but do you think the main issue is the battery your using does not supply enough power for everything? Instead of a spike maybe it's a voltage drop. Do you have a 12V deep cycle battery on the boat?
 

Trueblue3

Recruit
Joined
Feb 28, 2015
Messages
2
I have two 1000a cranking batteries in parallel. Don't think that's the problem. Going to make one more pass at trying to solve problem by isolating the voltage supply and put a sleeve shield on the wires to protect from noise. Hope it works.
 

blackhawk180

Petty Officer 1st Class
Joined
Jun 14, 2012
Messages
367
That's a new one to me, TB3 but I suspect you are heading in the right direction with shielding and battery source isolation. I have a similar setup (9.9 bigfoot with speed control) but connect to the main motor with linkage. Having the two tied together helps a ton with steering and leaving the main in the water produces enough drag to allow the kicker to run above low idle which it seems to prefer. It works so well for me I've never considered adding the remote steering option.
 
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