321 Ignition system woes

[AdamCermak]

Folks,

I've had an intermittent problem with the ignition system on my '99 321, and am looking for some insight. My summary and notes are below. Any thoughts you can spare would be greatly appreciated!

Adam
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Ignition problems


1999 Beneteau Oceanis 321, Yanmar 3GM30

original instrument panel (Yanmar type B)

ignition switch replaced July 2016 (has since worked fine, except as detailed below)


Symptoms:


When ignition switch is turned with the key, the ignition panel does not respond (no alarm, no lights, push button to start fails)

Battery checks show 12.8+v (using both built-in analog meter at panel, and external hardwired electronic meter)

multimeter across the terminals of the ignition switch shows 12.8v


Tests:


Able to hotwire and start the engine without problem at the engine, with a remote starter switch (https://actron.com/content/heavy-duty-remote-starter-switch) between the positive terminal on the starter and the S-terminal on the solenoid.


Removed the positive lead from the ignition switch and put it in the stack with the three leads on the negative lead of the switch, and clamped them down with the nut - no response from the ignition panel.


Sandpaper cleaned the positive lead to the ignition switch to make bright. No change.


Other Notes:


The ignition switch and panel worked fine three days before, at least twice.

I have not replaced the (notorious) ignition wire from the push button to the S terminal on the solenoid.

But, the ignition switch and panel failed in the same manner once before, two weeks ago. But only once. Later the same day, it worked fine.

The ignition switch uses SS nuts on the top and bottom of each terminal. This is clearly not optimal for the bottom, where it would be better to have a conductor.

The 321, like many (all?) Beneteaus, has three battery switches, one each for bank 1 (start), bank 2 (house), and negative (!). Could they be oxidized enough to impede starting?

I know of no fuse in the positive lead to the ignition switch, but the wiring diagram shows one. The ignition switch failed (two weeks ago), then was fine (same day, and three days ago), without me changing a fuse. Where is this thing?

Could the alternator be bleeding off the current from the battery?

 

[Stu Jackson]

99% of all intermittent electrical issues are connections. You need to start tracing wires to find out why your power sometimes fails between your batteries, main electrical switches and the cockpit panel. Just "doing" the back of the switch does not answer that question. Good luck.

 

[Charles Erwin]

Note that the key switch furnishes 12+ to the panel and start button.

This 12+ path is: battery to fuse to key switch. Test red terminal at key switch for 12+. Also verify the key switch passes 12+ to its white terminal at key on. If no joy locate/fix in-line fuse (likely wrapped with tape in the wiring harness) at rear left of motor block proximate to the starter.

12 - is supplied to the panel (lamps and warnings) from the motor block. So if 12+ is present at key switch then verify 12- cable (battery to motor block) is fastened clean and solid (likely it is not) also in your case pay attention that the 12- switch is not bogus.

Charles

 

[DougM]

Note that the key switch furnishes 12+ to the panel and start button.

. So if 12+ is present at key switch then verify 12- cable (battery to motor block) is fastened clean and solid (likely it is not) also in your case pay attention that the 12- switch is not bogus.

Charles

Check the 12+ primary From the battery to the starter. The nut that secures that cable to the starter can loosen at the starting motor as well as at the posts on the solenoid.

The white wire from the key switch to the starter solenoid is notorious for causing issues. too many connecters in the factory harness.Bypass the factory wire completely and run a heavier gauge white wire direct from the switch to the solenoid.

 

[Charles Erwin]

DougM and Stu Jackson's comments remind me that I overlooked something that might prove useful.

There are (at least) two pair of in-line plug connections in the wiring harness. These transmit 12 + and 12 - from the motor proper to the panel. They will be found in the harness at or nearby the starter on the left side rear of the motor - right close to the in-line fuse previously discussed.

Be sure to unplug, inspect and clean these connectors because a failure (usually corrosion) at these connections is the only failure mode that can be reconciled with all the symptoms that you list.

Maybe something like this:

Photo from Kloudie1

Charles

 

[Stu Jackson]

Be sure to unplug, inspect and clean these connectors because a failure (usually corrosion) at these connections is the only failure mode that can be reconciled with all the symptoms that you list.

Charles and Doug are correct. If you do a simple search on this or any other boating forum for "wiring harness" you will find that the notorious trailer connections altogether too many builders built into their boats for ease of construction, NOT continuity of service, are just plain horrible. Instead of simply cleaning them, replace them with butt connectors and/or replace the wiring completely (usually not necessary except for the ignition wire to the solenoid in your case as recommended). The wires are usually OK, but the connectors are crap.

 

[kloudie1]

The problem is usually in those bundle connectors that are adjacent to the green fuse holder.. As Stu says, you can clean them (again and again) or replace with good connectors.. Usually when not under load, you can measure 12+ volts at the switch but as soon as current starts flowing (push start switch) the bad connections drop so much voltage that nothing works.
(Thanks for the picture credit, Charles)

 

[cymeyer]

Had the same issue on our B321. I thought it was the starter motor, but not at all. I had someone in the marina help me run a solid wire from the starter button to the starter about 12 years ago and never had the problem since.

 

[Benny17441]

Your boat is not old enough but may have been sailed hard. First check the connectors like others have suggested but do not discard a loss of continuity in the wiring harness. The harness between engine and panel is usually routed around fiberglass corners with sharp edges and it is not uncommon for chafe in the wires of the harness to develop as a result of hull flexing. Peeling away of the insulation leads to erratic behavior of the buzzer and warning lamps and even including total loss of power to the Key switch. The wire to the solenoid is a well known critter that when it gets old it may fail to deliver full voltage to the solenoid resulting in the usual complaint of pushing the starter button and nothing happening. If after fixing power to the panel you still have starter push button issues you may relocate the button to somewhere near the engine compartment. Similar to your remote switch but with a fixed installation.