Yanmar Starting Issue - H380

[Capn D]

First off, thanks to Ed Schenck for the drawing and information on Yanmar's starting problem.

We had the same problem this weekend. Frustrating thing was the batteries (new) were showing 12.5v but still would not turn over the starter. Commodore was "thrilled" to have to handle the boat towards a safe anchor location while I beat on things and prayed to neptune below.

Here's the question: I purchased a Cole Hersee relay (MUCH cheaper on Amazon than Defender or WM). Looking at the drawing and having inspected and cleaned the wiring harness connection points - I see and noted the reference to the "white" wire. Looking at the ABYC color standards, I can't find "white" as a standard color. Did Hunter or Yanmar go color blind or am I missing something?

Call me ADD/ADHD/whatever, but if I'm going to start pulling new wire, I'd like to stay within the marine standards.

 

[splax]

similar problem

I pulled my engine panel to bridge that "white" wire to help my starting issues, but without a white wire I had no idea what I should do.
I found that by replacing a bad positive cable to the selector switch my troubles disappeared, so I tabled the wire augmentation. I have attached the wiring relay diagram that I intend to use as an eventual remediation to the issue.

 

[Dan Johnson]

Relay wiring...

Here's wiring pix and diagram of how the "supplemental" relay is usually installed.

 

[Capn D]

Re: similar problem

Randall, can you post that diagram a bit larger? That's a great diagram showing the color coding of the harness. I've opened up the panels under my pedestal and inspecting all the existing cabling. Already I have found two connection points with corrosion.

Because we are taking this boat to the coast soon and have some extended cruising planned, I want to fix this issue via the solenoid, plus add an emergency starter switch in the engine compartment.

 

[splax]

I'm sorry, but I can't find the source documents.

 

[Capn D]

I'm sorry, but I can't find the source documents.

No problem! I've documented all the spare cables I found in the pedestal. Two of them, I'm pretty sure, are for a courtesy light at the base of the pedestal that isn't there. The rest have me stumped.

 

[artboas]

Here is an explanation

No problem! I've documented all the spare cables I found in the pedestal. Two of them, I'm pretty sure, are for a courtesy light at the base of the pedestal that isn't there. The rest have me stumped.

Ok, the problem with these posts is that it is showing wiring, but not really explaining what needs to be accomplished.
With this info in hand, wire colors, etc., won't be that important.
So, here it is:
On the Yanmar engine there is a starter solenoid.
It is activated from the key switch. So, when you turn the key switch, the starter solenoid gets 12 volts.
Now, the solenoid needs a bit of current to operate properly. If there is any resistance in the wiring harness, key switch, etc. there won't be enough current at the starter solenoid to kick it in.
So, the solution to this is to install a relay. Why does this help?
Well, because the relay coil needs far less current to operate than the starter solenoid.
Now, the relay has 4 connections:
2 coil connections and 2 contact connections.
The coil is simple:
One coil terminal connects to ground, and the other to a 12v signal that comes from the key switch. So, when you look at the key switch, measure with a meter the terminal that goes to 12 volts + when you turn the switch to the "start " position.
Now, there are the contact terminals on the relay.
One of the contacts connects to 12v+. You must do this through an inline fuse. 3 amps should be fine.
The other relay contact terminal connects to the starter relay.
You can leave the existing feed from the key switch attached.
So, in summary you are providing a secondary 12 volt control to the starter relay, which will work at much lower current than the starter relay draws.
Hope this is helpful

 

[Capn D]

Thanks Arboas,

Actually, I realized I diverted from the original post. When I first reviewed Ed's diagram, I mistakenly thought I had to run a new cable from the pedestal. Before realizing my error, I had opened the panels in our aft berth under the pedestal and found a whole series of cables that were wrapped up in a coil, but going nowhere. I don't like undocumented cables!

Yesterday I did install the solenoid and all is well. Now, to figure out the purpose of these extra cables.

We are moving the boat in the spring to the coast and I will be spending plenty of time with cabling as we add a chartplotter, radar, etc.

Thanks for your help.

 

[fabrik]

if i understand this right i need the relay and a fuse box
Capt Michel

 

[DavidR]

location

Where do you place the relay? I realize it needs to be close to the starter, but is engine heat a problem for the relay. Is there a relay that withstands heat? I'm thinking of placing it near the engine access panel in the aft state room.

 

[artboas]

Close to starter

Where do you place the relay? I realize it needs to be close to the starter, but is engine heat a problem for the relay. Is there a relay that withstands heat? I'm thinking of placing it near the engine access panel in the aft state room.

Mount the relay reasonably close to the starter.
Engine heat is not an issue

 

[Bill Roosa]

The problem is you are not getting enough voltage out of the starter control wire to the solenoid. Ask yourself what are you accomplishing if you install a second solenoid inbetween the control wire and the old solenoid? Eventually the second soelnoid will begin to act up just like the oringinal one because it does not have enough voltage on the control wire to activate it.
You need to fix the voltage problem in the control wire not treat the symptoms.
Most of use do not do engine changes very often so it is safe to neuter your engine wiring harness of all the quick connect fittings. This completely fixed the problem in my boat and got the temp and oil pressure gauges (their wires also run through those quick connects and they had corrosion too) to read like I thought they should.

 

[robertsapp]

I'm with Bill on this

Installing an additional solenoid is a work around, not a fix. Run a continous length of #10 wire from the key switch to the starter solenoid and you'll permanently solve the problem, not just treat the symptom. Plus it's the cheaper way to go, unless you're paying someone to do it for you, because it does take a while to route the wire.