Electrical gremlins are killing me, actually just one

[billnorman1]

I started having intermittent starting issues on my DF 175 about a month ago. I had to withdraw from a tournament last week because I was afraid I'd have to be towed in.
I unloaded the boat and hit the starter but it cranked what seemed slowly and didn't start. I jumped the lowest T/M battery to it and it started but didn't want to stay running, but eventually settled down. I went across the Upper Bay to my best fishing spot but when I got there it was grass and slime covered and I caught nothing. Hard to start there I went to my second best spot, fished there...nothing, and very hard to start again. I'd seen this happening intermittently for about a month, but now it was getting very serious. I went to my third spot, drew a blank and it would not start there but it did crank over fast. I used the trolling motor to troll about 1/4 the way across the Susquehenna but it started again so I went back to the launch point. Sometimes it would crank sometimes not sometimes just a loud click. I figured it was the solenoid which is part of the starter so I ordered a new starter. Changed the starter yesterday it does the same thing. It'll start turning the motor over then stop SOMETIMES, and sometimes it spins it over quite quickly sometimes slow sometimes just a click or clatter. Those are the symptoms of a bad solenoid, or starter.

SO I changed out my main battery, a Duracell 31 AGM with a different one I had in the shop.

One heavy mother! Same damn thing. I have inspected the cable ends, they are factory and look good. I tore out the ignition and kill switch to inspect the connections but so far I see nothing. That still doesn't explain slow or intermittent cranking with a "click". I have an excellent electrical background, it seems like the main big wires going to the starter are developing some resistance internally. Maybe they are fracturing inside the insulation from turning the motor back and forth.

I checked the resistance to turning ( I have the plugs out and top plastic cover off) and it can be turned by hand with the appropriate amount of effort at the flywheel.

More to come but right now, I'm still troubleshooting. I need another person to take measurements at the motor when I crank it, I think I'll make a test light so I can see the voltage/current when I crank it.

More to come.

[fishingteach]

You need to do a voltage drop test across the main battery cables at connection points. You should not have more than 0.5 volts across any connection.

[Tim Kelly]

Do a resistance test on the cables, that should tell you if they're breaking down too.

[fishingteach]

Voltage drop tests are the best way to find unwanted resistance. Just measuring ohms with an ohm meter is inaccurate.

[billnorman1]

Yeah, right now I'm only one man. I'm going to make up some jumper cables with a light to test this out, going to go from the motor ground, which is right at the starter, to the motor +positive at the starter input. The entire motor is clean with no corrosion visible anywhere. Somewhere I'm dropping a huge wattage.

[Moonlighter]

Also check the white wire - the battery sub wire that powers the ecu. Should be attached to the + side of the master battery switch or the + of the start battery. It should also have a large fuse in it nearby. Check the wire condition, its attachment, and the fuse and fuse holder for corrosion.

There is a sticky thread on the Suzuki outboards parts forum with more info:
https://www.suzukioutboardforum.com/...-power-failure

[CatFan]

Don’t see any mention of checking the outboard charging system or battery state of charge. 5 minutes to test both and most likely problem source.

[billnorman1]

Also check the white wire - the battery sub wire that powers the ecu. Should be attached to the + side of the master battery switch or the + of the start battery. It should also have a large fuse in it nearby. Check the wire condition, its attachment, and the fuse and fuse holder for corrosion.

There is a sticky thread on the Suzuki outboards parts forum with more info:
https://www.suzukioutboardforum.com/...-power-failure

The voltmeter on the dash reads about 12 volts with the key on and the motor off, goes up to 14+ or- when running. I checked the at rest voltage of the battery with a Fluke, it was 12.65.
I have been running the Sam's club Duracell size 31 AGM. I thought it was 3 maybe 4 years old. I took it to Sam's this morning. I watched the girl put the electronic test meter on it. It came to 150 CCA and the red fail light illuminated. The battery is rated at 800 CCA's. I took a new one off the shelf, she checked it it rated 1050 CCA as it sat, not recharged. Boy was that good news. The shop battery I put in motivated the starter every time, so I'll take it out and put this new $180.00 one in and reassemble the motor.
I asked her if she could tell how old the Duracell I had been using was, she checked the code, 8 years old. Time flies when you're having fun I suppose.
I was one of the first ones here using the Sam's Duracell looks like I got as much use as I could out of this one.

[th365thli]

Glad you got it figured out! 8 years is getting your money's worth.

[billnorman1]

Well, I still have to put a lot of motor back together and put that heavy muther back in. I have the plugs out, they looked a little rich, I did a compression check (O.K.) and they are a year old I think I'll put some Iridiums back in.

[Moonlighter]

As you have discovered, these engines do not play nice when they dont get good power supply to the ecu. They might start, but wont run well, may suddenly stop running, or there can be multiple false engine fault codes flashing.

So the first port of call is always to check power supply, check battery charge, clean and tighten power connections and make sure there is no corrosion in wires and especially that white wire that powers the ecu. Some dealers took shortcuts and attached that white wire to the + lug on the starter motor instead of running it thru the rigging tube to the mastr battery switch or start battery itself, and that is a recipe for trouble.

[billnorman1]

Presently changing the sender for the trim/tilt which was bad too. It's really hard to get to. Got the motor disconnected from the tilt ram and supported with jack to get behind the T/T unit to get at the sender. New one going back in. This is a real hard job (for me). Also probably going to put in new neutral switch while I'm at it, due to play in Morse unit or old age it sometimes is not actuated coming out of reverse and I'm not going to change the throttle assembly if I can help it.

[billnorman1]

Got new plugs installed, put in the trim sender (had a part left over) put in the neutral safety switch, put the ignition switch and kill switch back in and put a new Duracell AGM31 battery in (damn that thing is heavy). The battery has METRIC nuts and studs, 8mm diameter. If you get a new Duracell battery use caution, a 5/16" locknut won't work.
Hit the key dry, no water in my garage, it fired right off, so I shut it down in half a second.
I'm waiting on a lost lock ring that keeps the tilt ram pin in. I put the snap ring plyers on it and *Ping* off it flew to God knows where. Soon as I get the snap ring I'm off to the water to try it out if the wind stops blowing.

[billnorman1]

Went to a Suzuki dealer and bought the lock ring yesterday, $1.35 or so. When I got home, the two I ordered ($8.52 shipped) had arrived.

[billnorman1]

O.K. took it out yesterday. The motor started eagerly every time. When I put it in the garage I put an external 10 amp charger on it for a couple of hours. Not related, the bow depth finder didn't turn on.
Looks like battery all the time. Trim and tilt indicator worked as well as the neutral safety switch. I probably killed the 8 year old Duracell battery not recharging it as often as I should have between excursions.

[Moonlighter]

Bill, I have these neat CTEK “battery comfort indicators” on both my batteries, the little light part is positioned using velcro where its easily visible at any time. The LED’s blink green, yellow or red depending on the battery charge.

My boat lives in the garage so I can easily keep an eye on the lights and when they blink yellow, I plug the CTEK smart charger into the connector on the lights, no need to even open the battery box.

https://www.ebay.com.au/i/4018407293...SABEgLQpPD_BwE

[billnorman1]

Sounds like a plan. If any of you buys a new Duracell battery they still use SAE 5/16" studs.
New nuts come with the battery but they are not locking nuts.