depthsounder experiencing electrical interference?

[Michael]

My Datamarine Corinthian Series depthsounder works fine when the engine is off. However, when I run the engine, or even turn the ignition on, it gives me off-the- wall readings (ie - going from 3' to 243'). I have tried regrounding it (to both the keel and the batteries) but with no luck. I have tried a noise filter (from Radioshack) with no luck as well. Any ideas ?

 

[Rpb]

Need help too !

My depth finder only works when I don't need it.It only gives me readings when it wants and It seem to me only in deep water . Anyone have any thought's . Rob

 

[Don Flowers]

depthsounder

Michael, where did you pick-up power for the depth sounder, and did you twist your power wires around each other when attaching them? It sounds like you are picking up clutter from an ignition wire.You may have to move where you attached to your 12VDC, or is your sending unit cable close to any large wiring such as power, ignition wire, or 12VDC cable. you may need to re-route your sending unit cable to an area where there is no interference. Hope that gives you some things to try and remedy. Let us know what the solution was to your problem. It surely is something like a wire location; that's what I would start with. Don

 

[Steve Feinsilver]

definitely a bad wire

Had exactly this problem on my last boat- depth worked until I turned on the engine. Found sort of accidently that a connection in the sending cable was a little loose- tightened it, put some electrical tape around it, and it was cured forever. Betcha something's loose.S/V Breathless h410

 

[Joe Mullee]

What about this problem???

My DS flies all over the place too. From 3' to 300'. Very quickly. Something like this:3,85,243,19,6,175,180, etc, etc......All this in a matter of seconds and it doesn't stop. With or without engine running. With or without anything else on.I've checked the connections at the transducer (thru hull type, just in front of the keel, next to the shower sump pump), the panel, and the display unit. Everything looks good. I'm not even sure what to do next. Any advice on where to look for the problem?

 

[Michael]

possible solution

from what you are describing it sounds like there could be a grounding problem. try grounding it directly to the battery to troubleshoot it. i still have no solution for my depthsounder though...if anyone has any more ideas let me know. michael

 

[Tim Donley]

Source and ground

Some intstallers will provide the electronics a "clean source" where as they provide the elecronics power to a sub panel that is directly sourced to the battery (with overcurrent protection)and return ground to the battery. By doing this the ground conductor is not sharing pulses returning to ground of the other equipment leaving the interference at a lower incidence if at all. Try wiring direct to test and see if it doesn't help, then establish a rewire plan.See Ya out there, Tim