Starting Problems Troubleshooting/Work Around?

[Jim]

Hi all, Hope everyone out there is set for a great 4th of July. Just ran into some starting problems with my 16 HP Atomic Universal Diesel. Basically seems like a toss- up between the Starter being in trouble or, more likely, the Alternator not delivering a charge to the batteries.  After a few outings where, unless the motor was already warm from a previous power-up, starts were getting to be more difficult, with seemingly not enough oomph in the crank...like one slow turn of the engine instead of the usual multiple turns. I recently had to use a power pack back-up to get the engine going so we could get back to the dock.  After a 15 minute run back to the dock and, on the following day, a cleaning and reseating of all the terminals on the batteries (one house/starter and one deep cycle), I was unable to start the engine. All I got was a one, rluctant turn of the engine and nothing else. Then, after charging the batteries for a while with my onboard charger, she turned right over, virtually instantly. So, although we'll need a few more easy starts like that to make the case, I think we're heading toward ruling out the Starter as the source of the problem, even though it is possible that we just got over a dead spot and such. Now then, despite my ammeter always reading on the plus side while the engine has been running, supposedly indicating the alternator is charging the batteries, and having spent last weekend motoring for about 7 hours, which should have provided more than enough charging time for any depletion of charge on the batteries until then, it seems like the alternator may not be adequately charging the batteries. And, it may be that this has been the case for quite a while, as starts have been a little tougher to come by during the last month or so, despite the weather here having warmed up quite a bit of late. I also should note that the voltmeter readings on each of my batteries have consistantly been more than adequate throughout the last month's activities, including the other day when we had to add the back-up power pack to get going and back to the dock. My experience with batteries and alternators, and the guages and systems provided to supposedly warn you of trouble, particularly on cars, and now I guess on boats also, is that they are all largely useless. I have gone through several failed alternators and/or batteries in my day and never, ever gotten an idiot light or an ammeter reading which warned of a failing battery or the failure of an alternator. This is a mystery I believe only the engineers of the world could begin to fathom, but that's another story...Anyhow, my real question is, if we have a fully charged pair of batteries which are in good shape, and the alternator is failing, shouldn't we nevertheless be able to get out there and get quite a number of good, easy starts with the diesel before the batteries drain again? Just looking to get this 4th of July weekend of sailing in, probably 5 or 6 starts in 85 degree+ weather, before going after this problem in force and fixing it. As I understand it, diesels only consume electricity with the use of their glow plug and for engaging the starter. So, if my recent experience is any indicator, it seems we should be able to get in quite a number of starts before we fail again. As well, we've also got the power pack back-up and, as a last resort, towing insurance... As well, we're talking Long Island Sound, with only the possibility of an isolated thunder shower in the forecast right now so, while I far prefer all systems up and running well when we go out, I don't think we are talking much risk here at all. However, your comments and thoughts are welcome as always, on both the starting problem itself and our weekend plan to temporatily beat it...Fair Winds, Jim

 

[Jack Tyler]

Start with the basics...

Jim:Hope you managed an enjoyable 4th on the water without too many engine problems. Assuming you're back and ready to tackle the cause vs. the symptom, I'd start with the simple things and work my way thru the whole system. You don't mention the age of your batteries, wiring or engine peripherals, so these suggestions can't be based on any of that info.1. I would remove ALL the wiring, clean the posts, recrimp new terminals where they may be suspect (WM will loan you a crimping tool) and even consider upgrading the wiring where it looks undersized, using a wire chart for 3% loss and measuring the *entire* distance between battery-solenoid-battery. Based on what you did describe, this would be my first suspect. I realize you mentioned already doing this but a second look, at all the terminals including the solenoid, alternator, engine ground and starter as well as batteries & battery switch, both + and -, while using lots of emery paper and finishing up with a spray of e.g. Boeshield after refastening...well, that would still be my first step.2. Buy or borrow a hydrometer and measure the specific gravity of each cell after the battery is dormant for a few hours or, better, overnight. I suspect your battery health, too. If you had decent electrical monitoring gear, you'd have another way to both graph battery voltage over time *and* alternator performance; you might want to consider this as the boat's next birthday or xmas gift. Jack Csenge and Jack Rabbit Marine offers reasonably priced systems, great support and good gear. A bad cell or two in the battery(ies) will defeat all attempts to charge them.3. For peace of mind and depending on the age of your engine, I'd pull the starter (only 3 bolts) and take it to a good marine/auto electrical shop. While there, ask them to upgrade the jumper wire that carries the starting current from the battery wire that runs to the solenoid to the starter. Typically, this is a much smaller gauge than the battery wire, is the first thing to heat up significantly when finding it hard to start the engine, and that just makes starts harder. You want them to bench test the starter under load, at a minimum.4. IME alternators usually fail fully when they go and you indicate you have a positive charge when running the engine. Did you measure voltage with your VOM? Was it up to spec (approx 14.6V and steady) while you apply loads to the battery e.g. bilge & fresh water pumps? Unless a problem is indicated here, that is most likely not your problem.Good luck. Be sure to tell us what you found when things appear fixed.Jack

 

[Jim]

Thanks For The Suggestions Jack

Thanks for the input Jack. We've not headed out for our weekend as yet, so the excitement is yet to come. Just for information purposes, I am working with a 21 year old engine and batteries that are at least three years old. The batteries were there when I bought the boat. I never use the starter battery for other than starting and also have a dual purpose battery for house use...which I keep to an absolute minimum use...just instruments, maybe FM and, as needed, VHF radio, and maybe a few times a season use of the running lights.I would have delved more deeply into this before this weekend but we've been having a highly humid heat wave and a half up here and working on board the boat has been pretty much impossible. Anyhow, you've provided a great grocery list of things to do which I will add to my plan of also getting the starter battery load tested when we get back. Thanks again, and have a great 4th...Jim

 

[Jack Tyler]

Re: a load test...

Jim, I should have thought to mention Nigel Calder's description on load testing a battery. It's in his Boatowner's Mechanical & Electrical Manual and, while it's better to read his description, the basic drill is to defeat the engine from starting, crank the engine for perhaps 15 secs while monitoring voltage drop across the battery terminals, and watching how much drop you get. A drop of 1.5-2V, as I recall, afterwhich the voltage holds almost steady, is a good report. A continuing drop after that initial 'first few seconds' drop is a failure. Read Nigel's write-up for a better description. And BTW, the partner test is to test the charging circuit efficiency: this is a great way to measure how much resistance exists in the 'alternator to battery' circuitry, something it sounds like you could use, too.Jack