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Asleep at the wheel
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Discussion Starter · #1 ·
We've had a pretty crappy season. Life has gotten in the way, and we haven't been able to get to the boat most of the season. Plus, when we've been there, the winds were too nasty (blowing us sideways in the slip and tough to get out) or the shoaling was bad enough that we really couldn't get out to enjoy the summer. However, by August I was ready to push on and really TRY to use the boat more.

I asked my dad to come for a ride with me in early August, and when we got there, the boat wouldn't start. The solenoid would tick on the starter, but the engine just wouldn't turn over. We pulled the starter thinking it was probably shot (it had been rebuilt last year). Hooked it up to the batteries with jumper cables, and it worked just fine. So we reinstalled it, and did more testing. We kept seeing weird voltage readings all over the engine, so we knew something was wrong. Plus, when I switched the glow plugs on, the fuel gauge would slowly show more fuel. I opened up the control/gauge panel and looked around, but didn't see anything too major. I did notice that the ignition switch was pretty loose, so we tightened that. We looked at a few more things, then gave the engine one last try, and low and behold, it worked. We came to the conclusion that it was the ignition switch (it was original to the boat).

I ordered a new switch, and in mid-August I replaced the old with the new. Tightened everything up, and the boat started on the first try. I was alone, and couldn't stay, so I let the engine run for a while, then left.

In late August we visited the boat, and again she started up almost immediately. It was too windy that day (need cheater lines and a bunch of other changes before I'd feel comfortable going out), but we left the engine running for about 30 minutes, then shut everything down.

We finally were able to get back out there yesterday. It was a BEAUTIFUL day. My dad and his wife arrived, and we (including my wife and kids) all piled onto the boat. We got settled, and I went to start it, and all I heard was the tick-tick-tick of the solenoid. We opened the engine compartment, and you could see the engine trying to kick over, but it wouldn't actually spin. We checked the battery voltages at the fuse panel, and both read at least 12.5 volts, even during our attempts to start the batteries. We double-checked the connections to the ignition switch, and everything was nice and tight.

So, now I'm left with two options, as far as I can guess. Either there is a problem with the starter (likely in the solenoid) or I have an electrical glitch, probably in the ground plane.

How would you go about debugging this? My thought was:

1) double-check the ground connection between the engine and the battery. It's possible that the wire has worked loose since the engine work that was done on the boat last year.
2) replace the ground wire between the engine and the batteries. If I do this, what gauge wire should be used?
3) use jumper cables to bypass the ignition switch and see if the engine will start, first using both the positive and negative terminals, and then using only the positive terminal. If it works with the first but not the second, then I know I still have a problem with the ground plane back to the engine block.
4) replace the remaining wiring in the wire harness for the engine. If I do this (and I know I need to get rid of the trailer plugs, which may be the source of the problem anyway), should I actually replace all of the wire, or just clean the existing wire and put new connectors on before hooking it to the busbar (I know that's not the right term, but I can't think of the right one now). If I replace the wire, what gauge wire should be used?

I know that for the wire gauge problems, I could just use the same gauge as what's there, but given that they also used the trailer connectors, and all of the problems that has caused people over the years, I thought I should ask just to play it safe.

Thanks in advance for any assistance. Hope everyone is well!

Oh, by the way, I'm also perfectly willing to just accept that my dad is the reason for all of the electrical issues. They only seem to happen when he comes.
 

Asleep at the wheel
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Discussion Starter · #8 ·
I'm getting ready to replace the wiring harness connections. Universal used trailer hitch plugs, and I suspect that's part of my problem. The battery terminals are clean - we checked that last time, when we determined it was the ignition switch.

I haven't checked the fuse between the ignition switch and the solenoid - I didn't even know there was one. The wiring diagram (http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&catalog=200140&model=M-20 / 5416&page_ident=200140-37&manufacturer=Universal&title=WIRING DIAGRAM&size=800) doesn't seem to show one. That doesn't mean it isn't there, though, and it's an excellent idea/thing to look for.

Thanks for all the feedback! I hope to get to this this weekend, and I'll report back afterward.
 

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Discussion Starter · #16 ·
Thanks for the feedback. Mark, if it wasn't for the fact that the starter motor had just been rebuilt about a year ago, I'd be inclined to agree with you. Heck, it's what we suspected was the root cause a few weeks ago when we finally "discovered" that it was the ignition switch. We had actually pulled the starter and tested it outside the engine. It worked just fine. Now, we didn't give it a thorough test (we were aboard the boat and didn't have a proper test bench), so it MAY still be the bad piece in the end. But right now, I'm inclined to believe that it is another electrical gremlin. I'm headed to the boat in the morning and my plan of attack is:

1) check (i.e., remove, clean, inspect (including, where necessary, replace), and reinstall) the ground on the engine block (the engine was worked on a year ago, and I can see where the ground may not have been "properly" tightened down, or may need to be re-tightened);
2) test the engine to see if it starts;
3) regardless of the answer in 2, replace the trailer connectors with bus strips like Denise showed in her picture;
4) re-test the engine;
5) remove the ammeter and install a voltmeter (including the alternator output rewiring suggested by MaineSail);
6) re-test the engine;
7) if it still doesn't start at this point, use the jumper cables to test the batteries and starter directly;
8) if it still doesn't start, use the spare, fully charged, known-good battery that I'm bringing along to try to jump-start the engine;
9) use a battery tester to check the two 12-volt batteries in the boat's battery bank to ensure they are still OK.

The wiring work up through step 6 needs to be done regardless, that's why I'm starting there. I suspect (and hope) that that will solve the problem. If not, at least I'll feel more confident that the wiring itself isn't the problem. I can test the impedance and voltage drop all along the starter's path, so I should be able to find (and fix) any problems. Then I will have narrowed it down to either the batteries or the starter, and having a known-good battery with me will help me at that point to determine where the problem lies. The battery tester will also give me an idea of whether the batteries need to be replaced anyway.

Denise, thanks (as always) for the comments! Hope you are well!!!
 

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Discussion Starter · #19 ·
I went to the boat today. Tried the engine, heard tick, tick, tick. Opened the engine compartment and thought about starting on the wiring harness replacement, but remembered that I wanted to do this systematically. I put a wrench on the ground bolt, and it didn't want to tighten. So, I decided to take it out and inspect everything. The bolt was indeed VERY rusty, and the ground back to the batteries had some corrosion on it, too. There were two other ground leads on there, but those looked OK. I had brought a cheapie Dremel-like tool with me, and as MaineSail suggests in his article about the wiring harness, I attacked everything with the stainless steel brush attachment for the rotary tool. The thing bogged down very easily, so it took closed to an hour to get everything clean. But I managed to get all of the ground lead connectors to be shiny, and I even got the bolt to look pretty good. I made sure to polish the inside of the head, since that's one of the contact surfaces. The threads looked a little beaten up, and it was tough to get all the corrosion/rust out of the space between the threads, but I did manage to get a lot out. I put it all back together, and noticed that the bolt was really having a hard time going in. I had had problems getting it out, but I assumed it was due to corrosion. I kept tightening the bolt, and could see the ground wires move and wiggle as it got tighter. I even got to the point where I think the bolt was bottoming out in the engine, but the grounds still seemed to have a little play. I would really have preferred them to be tighter, but I just couldn't snug the bolt any more. I went up to the cockpit, and the engine started right away!

My guess is that when the shop put the engine back together last year, they tightened the bolt, but didn't check to see if there was play in the ground wire. I bet there was already some play in there, and then over the course of the very cold winter last winter and the vibrations, etc., this season, the bolt came out a bit. I want to get a washer or two, and/or a new bolt, but for now everything is running.

Thanks again for all the help and feedback!
 

Asleep at the wheel
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Discussion Starter · #23 ·
We had a chance to go for a sail this past weekend. Got to Dragon Wing around 3:00 PM, and decided I would start the engine before doing anything else. My wife sat there watching me, unsure whether it would start. Turn the key, and it sounds like the engine is starved for fuel. Adjust the throttle and try again, but nothing. Then I realized, it was 50 degrees out, and I hadn't used the glow plugs. Turned 'em on for 30 seconds, then turned the key and the engine fired right up! We had a nice, although short, sail and were back in the slip before 6:00 PM. Other than the fact that our time on the water was limited, I don't think the day could have gone better.

I'm still waiting to see what happens next time my dad is aboard! :)
 
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