Outboard/auto pilot problems

[Georgio]

Any suggestions welcome. . .

My 24ft sail boat has a Yamaha 4hp o/b that charges the batteries through what appears to be a regulator of some type (it has an amp meter on the front). My old ST2000 (must be 10yrs old??) works wonderfully under sail but starts to go crazy when the engine is started.

I have checked the output from the regulator, it is 17-18V when not connected but this drops down to around 13-14V once connected up to the batterie(s)

The engine is a good 6-7ft from the autohelm controll box so shouldn't cause magnetic problems??

Any Ideas, from memory all seemed to work fine last year when I fitted the autohelm. After 15hrs of motoring around lands-end a few weeks ago I need to get this sorted!!!

Oh, I can't speak highly enough of my old Yahaha 2-stroke, must have done 80hrs of motoring on my trip scotland-solent and despite dunkings and general abuse it didn't complain once and was totally reliable. well done Yamaha

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[Alex_Blackwood]

Could be you are picking up interferance from a cable run, not the engine! Check your cable runs, especially the one from the engine to your "Regulator" if they are running alongside any of the cables for the autopilot then it could be that you are getting pickup. The answer is to seperate the cables by at least 50mm. Not always easy in confined spaces but get the seperation as large as possible, if cables have to cross make the crossing 90 deg.
Pickup is most likely to occur from inductive or capacitive coupling from alternating current although spikes and ripples in your dc circuits could have an effect.
Also worth considering, if it was OK last year. Have you installed any new. or altered, equipment positions, or cable runs since?

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