Auto helm revisited

[rpoe959190]

First thanks to all for answers to the last auto helm question.
When I am in the "auto" position with my st 40000 and start the engine it kicks out and goes to "stand-by". The unit was just replaced by a new one this spring. I dont remember the original 1994 model kicking out when I started the engine. I have relocated the fluxgate to a position close to the center of the keel area and there isnt any metal or electrics to interfere. My batteries are new as of last April and hold a good charge. Is this a normal mode of operation for the newer auto pilot?

Rich
Enchantress 1284

[Stu Jackson]

Rich

Our old ST3000 and our new ST3000 ALWAYS did that.  Rather than concern myself with its behavior, I just turn it off when I hit the start button, and then back on.  We have the unit mounted on the starboard coaming, with a separate power switch under the helsman's seat, so it's easy to do.  Don't know how you switch the on/off power for your ST4000, but going to standby and then back to auto should also work.

Stu

[Roc]

I always flip on my Nav instruments and autopilot AFTER my engine is started.

Roc-

[rpoe Enchantress 1284]

Thx for the info guys. Now I have another situation. Under sail with the auto helm engaged when the refridge comes on AND when it goes off the auto pilot returns to stand-by mode. The batteries are fine and the fluxgate was moved to the futherest forward they could locate it at the keel. The fridge is in the lower starboard aft storage area. Any Thoughts?

Rich
Enchantress 1284

[Tom P, IMPULSE #233, '86]

Rich,

I believe your Autohelm problem is related to a loss of power (voltage) to the Autohelm; i.e. everytime a high voltage draw occurs (engine starter, refer, etc), your autohelm looses the voltage required to keep it active...

This voltage drop may only occur for a very short amount of time (a nano-second?), but is enough to drop the autohelm processor off-line...

I think the only way to truly monitor for a power drop at the autohelm would be to monitor the voltage using  an O-Scope...Of course O-Scopes are very expensive and may be difficult to borrow...

If it were me, I'd check a few things...

1. Is that the newer autohelm more sensitive to voltage drops than the older unit...Newer technology, newer processor/chips; might be more sensitive...

2.  Are there any other items on the same circuit with the autohelm?  If yes, make sure they are off...

2.  Check to be sure the proper size power wires were used for the autohelm---the longer the wire run, the larger the wires should be...

3.  Check for loose/corroded connections on all the electrical components on the boat...A loose connection anywhere will cause an additional voltage drop...

4.  Maybe your batteries are just not big enough or in good enough shape to handle the power draw you are subjecting them to; all the items you mentioned (starter, refer, autohelm)  draw a large amount of current when in use and are very taxing to the batteries...Maybe the batteries just can't handle the load---if you try to start your car with the headlights on, the lights dim don't they???

Hope this helps,
Tom

[tassber2]

Check your wiring and all connections between your unit and your battery.  I would jump wire your autohelm directly to your battery to see if you still have the problem.  Don't forget to check your ground circuts and clean the connections all the way to the engine block.  The other possibility may be that your starter is drawing way too many amps and might need attention.  Good luck

Mike
1996 MkII #1321

[seacatc34]

Once upon a long time ago (before my C34)...my depth sounder stopped working.  I checked this and that and concluded it HAD to be the through hull mounted transducer.  So I bought a new transducer and had it professionally mounted in place of the old one, all at considerable expense.  Wouldn't ya know... that did not fix the problem.  Turned out the battery, which was fairly new, was too run down to power the transducer, although lights and radio worked.  After putting the battery on a charger, the sounder worked fine.
  Morale (as others have pointed out):  Always verify adequate power is getting to the load under operational conditions.  Continuity checks aren't  sufficient; corrosion may reduce voltage enough to cause failure while still allowing a good continuity check. Ï

[Brad "Captivated" # 1285]

The owners manual that comes with your Autohelm says that in the event of a voltage drop the unit will revert to standby mode. I have had this happen when starting the engine. So now I just switch the auto pilot off whenever I start the engine.
It is a minor inconvenience-like disconnecting from the shorepower. And so it goes...

[Stu Jackson]

Based on a recent experience with our fridge, which was not cycling correctly, we replaced the wiring from the fridge to the panel.  Only after we did that did we find that the little jumper wire behind (inside) the electrical panel, from the main DC bus to the power strip to the fuses and switches (yeah, it's a 1986 boat!) had poor connections.  That was what was throwing the fridge off.

Check the jumper wire.

Try this:  http://c34.org/bbs/index.php?topic=3044.0  scroll to the second page

[Roger Blake]

As another note...and you may have already done this or the PO may have...the autopilot must have its own power supply. You can't connect it to an existing power supply for other instruments. I ran my dedicated ST4000 power supply thru the pulpit, down the chrome posts, back to the electrical panel...to its own switch.  I haven't had any of the problems mentioned in this posting.

[Larry Robertie]

The owners manual that comes with your Autohelm says that in the event of a voltage drop the unit will revert to standby mode.

Pg. 16 of the manual to be precise.  It states that the ST4000 reverts to standby at 10v (+/- 0.5v).  That should be a very unusual occurrence as it is way low.  In fact, if you had it connected directly to the batteries and it did this you would be pretty safe in saying the battery was dead.  This sounds like a temporary (and extraordinary) draw from your fridge.  I'd say you have a bad connection in there that is drawing much to much power when the fridge kicks on.  Rather that trace the draw I'd rewire to make sure of a dedicated (and clean) connection.

For anyone interested, here's a PDF copy of the manual - http://www.robertie.com/Ruach/Manuals/ST4000plus_mk2.pdf