The Blue View - Troubleshooting an Alternator

Cape Town just never wants to let us go. Every time we've tried to leave, some malfunction occurs. When we were last here in 2007-8, we had done all our pre-departure checks, had cast off the lines and were backing out of our slip when the gearshift lever came loose. We were stuck in reverse, heading down a narrow, dead end channel with expensive boats on either side, and the old adage, “aim for something cheap”, came to mind. At the very end was an old concrete work-boat wharf. I headed for it, and killed the engine. Between the two of us, were able to fend off and tie up long enough to make the repair with only minor damage to the teak brightwork.

This time, we didn't get far before the headsail tore, the alternator went on the fritz and the backup cockpit GPS stopped working. Now that we have a few weeks grace on our visas, we handed the headsail over to a local sailmaker and bit the bullet to have a new one made, but the alternator and GPS are mine to troubleshoot.

Cups has a simple charging system. Our house batteries are all in parallel, and connected directly to the alternator output. The starter battery is isolated from the house batteries with a diode and a thermal breaker (See the Blue View on charging two battery banks). The alternator is a high output P-type with an external Balmar voltage regulator. The regulator senses the battery voltage and controls the alternator output by varying the alternator field current.

Our alternator was working when we started the engine and left the marina, but sometime in the next half hour, the output current went to zero and it stopped charging the batteries. There was no alarm. The original symptom was that the engine voltmeter was reading 12.25 VDC. If the alternator was working, the voltage would have been well over 13 VDC. I went below and checked my battery monitor and confirmed that the alternator output was zero.

This is the process I used for troubleshooting the alternator :

Visual Checks Marine alternators and electronics are pretty robust, and while they do fail on occasion, there is a much higher probability that the problem is something simple like a loose or corroded connection or a loose belt. I inspect the obvious things first – is the drive belt loose; are the alternator connections tight; are the regulator connectors tight; is there any sign of corrosion on any of the connectors, connections or wires; any loose or broken wires? Often the problem is obvious, and if you spot something flaky, but not causing a problem at the moment, fix it now before it does become a problem.

Initial Checks For the initial checks, I use a digital multimeter. I shut down the wind generator and disconnect the solar panels (actually it is easier for me to drape a tarp over them), then measure the voltage across the positive and negative terminals of the house batteries. It is typically around 12.6 VDC, but could be anywhere form 12.25 to 12.80 VDC. Then I measure the voltage between the positive and ground terminals of the alternator. Since I don't have an isolation diode between the batteries and the alternator, I expect the voltage to be close to the the same as the battery voltage. (If I did have an isolation diode, I would expect the voltage across the alternator to read 0 VDC). If the alternator voltage is not the same as the battery voltage (or 0 VDC if an isolation diode is in place) then the problem lies between the alternator and the battery.

Things to check are: Cable and connections between the battery and alternator. Ground connection from the alternator. Blown fuse - although there is rarely a fuse in the connection between the alternator and battery Open current sense resistor (these are used by battery monitor systems to measure alternator output, and have been known to overheat and open). If there is an isolation diode in the circuit, it may have shorted.

If the first check was okay, I start the engine, let it idle for a minute or two, then increase RPMs to 1/3 full throttle. The voltage across both the alternator and battery should increase by at least a volt. If not, the problem still exists. If the alternator voltage did not increase, the problem lies with the alternator or regulator If the alternator voltage increased, but not the battery voltage, then the problem still lies between the two.

Things to suspect: Open isolation diode High resistance in the cable or connections between the alternator and battery.

Alternator Checks If I've gotten this far, there is a problem with either the alternator or the regulator, and the next step is to determine which one. To do this, I first simulate the voltage regulator using a test lamp. The lamp must draw at least 1 amp – I use an old 24w 12 VDC anchor light from the pre-LED days, and to which I have soldered two 18” wires. I test the bulb by connecting it across the battery. I disconnect the field wire from the alternator (on my alternator, the field terminal is marked “FLD”, but it may also be marked with “F” or “FIELD”), and I connect one lead of the bulb to it. I start the engine, then connect the other side of the bulb to 12 VDC. If the bulb lights up, the alternator is a P-type, and the alternator output voltage should increase. If the bulb doesn't light, the alternator is either an N-type or there is an open field circuit. Remove the lead from the 12 VDC and connect it to ground. The bulb may or may not light up, but the alternator output voltage should increase when the bulb is connected from the field to ground.  In either case, I watch to see whether the alternator output increases and decreases as I connect and disconnect the bulb. If the alternator output doesn't change when I connect and disconnect the bulb (and I am sure the bulb works), the problem must lie with the alternator. Depending on the situation, I may dig out the spare alternator and swap the bad one out; try to diagnose and fix the problem; or take it down to the local alternator repair shop. I've done each of these at one time or another.

Regulator Checks On my Balmar voltage regulator, there are a host of connections – battery voltage sensors, battery temperature sensors, alternator temp sensors, tachometer connections, etc. Most are optional, or, as is the case with the battery temp and voltage sensors, will generate an error message if there is a problem. The first thing I do if I suspect a problem with the regulator is start the engine and see whether an error message is displayed. If there is, I use the Balmar manual to diagnose the problem. If there is no error message, there are four connections, power, ground, ignition, and field,  that can cause the symptoms I have, and will not generate an error message.

The following is the procedure I use to determine the cause: With the ignition off, I measure the voltage between the power connection and ground connection. It should be close to the battery voltage. If it is not correct, find the problem – it might be a blown fuse or a bad connection - otherwise continue. I start the engine and measure the voltage between the ignition connection and ground. It should be between 11.5 VDC and the battery voltage. On Nine of Cups, the ignition connection is routed from the battery, through the ignition switch, then through the oil pressure switch, and finally to the regulator. If not correct, find the problem – otherwise continue. With the engine running, I measure the voltage between the field wire and ground. It should be between 3 and 10 VDC. If not, and there is no error message, the controller is faulty – otherwise, the regulator is working.

So what did I find? The problem turned out to be the connection on the oil pressure switch for the wire that connected it to the regulator. The pressure switch was fine, as was the connection to the cockpit engine alarm. It took an hour or so to find the problem and another hour to replace the connector with a shiny new ring terminal – then, of course, most of the rest of the day to write the blog about it.

The Blue View - Pre-Passage Rigging Check pt. 2

Deck Level

Note: this is Part 2 of our pre-passage rigging checks – the deck level checks. Part 1, in the last Blue View, detailed the checks I do aloft.

General Checks These are much the same as the general checks when going aloft. I do a close eyeball check on all the fittings and wire before cleaning the rust – sometimes the rust can point to a problem. Then I clean the fitting with a good metal wax and inspect the part again, looking for any cracks, distortions, worn or stressed parts, elongated holes, missing split pins, loose or missing bolts, etc. - in general, anything that doesn't look right. I also look closely at the wire for any strands that look cracked or broken. We have Stalock fittings throughout, but if we had swaged fittings, I would also check for cracked or swollen fittings. I renew any worn or loose whipping on line ends.

Mast, Shrouds and Stays I first check the mast alignment. It should be straight side to side, but may have a slight curve aft towards the top. I check the tension in the stays and shrouds – they should all be tight and there should be minimal or no sag in the forestay and staysail stay. I closely check all the turnbuckles to make sure none are cracked or galled, and that the legs of all the split pins are inboard. I remove the cover over the mast boot and check for cracks or deterioration in it, as well as the mast collar. I check all the blocks at the mast base.

Chain Plates The chain plates attach the standing rigging to the hull. Ours pass through the caprail and are glassed into the hull. Except for the very tops, which are exposed, they are virtually impossible to inspect. I check them closely, looking for any hairline cracks, elongated holes, or signs of moisture that might be making its way downward.

Boom Like the mast, the boom is aluminum and has a number of stainless screws attached to it, all of which are subject to galvanic corrosion, and I check each of these. A sure sign is bubbling or swollen paint around the screw head. I check the ends, connections, sheaves and welds for corrosion and cracks. I check the outhaul and reefing lines for smooth operation and any signs of chafe. I spend a few minutes examining the gooseneck for cracks and tightness.

Halyards, Topping Lift, Sheets My checklist for halyards, topping lift and sheets includes: Check all for chafing Check all fairleads, blocks and sheaves Check the mainsheet traveler for cracks and general operation.

Furlers Furler checks are a bit time-consuming, but I'd rather fix a problem here in port than at sea. Remove the sails and check both furlers for smooth operation. Flush the bearings with fresh water. Inspect the lower swivel, furler drum, etc. for any signs of corrosion, especially around the stainless screws. On our Harken furlers, I loosen and re-tighten each screw, adding Tef-Gel to any that show signs of seizing or corrosion. Check that all shackles are in good shape and properly seized. Check the furling lines for chafe, and inspect the fairleads and blocks.

Rope Stoppers, Clutches and Cleats I check all for burrs and tightness and check the operation of stoppers and clutches.

Tracks and Cars I check all tracks for corrosion, burrs, etc. Then, I check that all cars are secure and move freely.

Whisker and Spinnaker Poles Since I just reworked the whisker pole, I gave this check a pass. Usually, I would check both ends for cracks, deterioration, missing or loose rivets. Check the outhaul, topping lift and guys for chafe and insure smooth operation. I'd extract and retract the pole to check operation.

Lifelines We have Dyneema (actually Amsteel) lifelines, and really like them. (Here is a link to an article in Good Old Boat magazine on the subject – although I doubt this particular author knows what he is talking about.) They have two issues, however. First, Dyneema exhibits creep, which means the lifelines continue to slowly stretch over time and need to be re-tensioned every few months.  Second, the Dyneema should be replaced every 3-5 years, due to UV degradation. The degradation is not readily apparent, so it is important to keep track of how long they have been in place and when they should be replaced. I also check for any wear at the stanchions, and check all turnbuckles, pelican hooks and shackles for cracks. All split rings should be in good shape and facing inboard. Inspect the stanchions for cracks or looseness.

So, what did I discover from our rigging check? Several small issues were corrected: Lifelines re-tensioned; several split rings needed replacing; first reef line, port side was chafed -  I was able to remove a few feet from the end and re-use it; a few screws were missing or loose on the stanchion bases; several lines needed re-whipping.

Unfortunately (or perhaps fortunately), a potential show stopper was discovered. The chainplates on the starboard side are showing some evidence of water ingress and possible corrosion. The chainplates are stainless steel, which is generally very corrosion-resistant and performs quite satisfactorily in marine environments.  It is very susceptible, however, to something called crevice corrosion. Crevice corrosion is a localized form of attack which is initiated when the metal comes in contact with moisture when there is a low availability of oxygen – such as in a crevice.  If moisture, especially saltwater, makes its way past the caulking around a chainplate and lies against the stainless, a perfect environment for crevice corrosion develops. Since the internal chainplates on Nine of Cups cannot be inspected without literally dismantling the cabinetry in the saloon, there is no easy way to determine how much corrosion has developed.

Losing a chainplate will almost certainly lead to losing the mast – not a pleasant prospect anywhere, least of all in the middle of a major ocean crossing. Many sailboats of the same vintage as Nine of Cups  that have glassed in chainplates have replaced them with external versions, heavy duty stainless steel straps that are bolted through the hull. We need to call in an expert or two to confirm our suspicions, but we are now thinking our departure from Cape Town, will likely be delayed.

Stay tuned...

The Blue View - Pre-Passage Rigging Check pt. 1

Upper Rigging

Before heading out on a major passage, I spend a day or two checking most of the systems aboard Nine of Cups. The engine, prop shaft seal, steering, bilge pumps, nav lights, thru-hulls, windlass, and a host of other items are all scrutinized and/or tested. Near the top of the list are the rigging checks.

The rigging consists of all the lines, wires and metal parts that hold the mast upright (the standing rigging) and which hoist, move and control things (the running rigging). A single failure in the standing rigging will quite likely cause the mast to break. A failure in the running rigging will, at the very least, cause damage to the boat – a torn sail due to a chafed reefing line, for example. In the worst case, a running rigging problem can cause serious damage to the boat, or serious injuries to the crew – the combination of a jibe and a chafed boom preventer, for example, could cause the boom to swing with such force that it bends or breaks on hitting a shroud, and/or knocks a crew member overboard.

Even worse is that a problem with the rigging is most likely to occur when it is being stressed, like during a storm, causing even small problems to quickly become big ones. That small tear in the mainsail due to a chafed reefing line will, within seconds, cause the main to become totally shredded if it happens in the middle of a storm.

Thus, I think it is important to find and correct any problems before we leave. In this blog, I'll discuss the checks I do aloft, and in the next blog, I'll talk about the deck level checks.

Tools It is always a dilemma as to which tools to take up the mast with me. Take too many and it's hard to find the right one when it is needed. On the other hand, it's a hassle when I am up the mast and realize I need another tool. My compromise is to take the minimum I'm likely to need, and a small line, 60 feet (18m) or so, with a weight attached. If I need another tool, I lower the line, then tap on the mast to get Marcie's attention, and she attaches the tool to the line. Here are the basic tools and supplies I take with me: A large and medium sized screwdriver, both flat and Phillips; large needle nosed pliers, large pliers, adjustable wrench, metal polish or wax; rags, spray bottle of water; and a pencil and paper for taking notes. Sometimes I take a small digital camera to document potential problems  and take pictures for Marcie.

General Checks I usually go straight to the top of the mast and slowly work my way down. I do a close eyeball check on all the fittings and wire before cleaning the rust – sometimes the rust can point to a problem. Then I clean the fitting with a good metal wax (I like Collinite metal wax) and inspect the part again, looking for any cracks, distortions, worn or stressed parts, elongated holes, missing split pins, loose or missing bolts, etc. - in general, anything that doesn't look right. I also look closely at the wire for any strands that look cracked or broken. We have Stalock fittings throughout, but if we had swaged fittings, I would also check for cracked or swollen fittings. The aluminum (aluminium for you non-North Americans) mast probably has a hundred stainless screws attached to it, all of which are subject to galvanic corrosion, so I check each of these. A sure sign is bubbling or swollen paint around the screw head.

Sailtrack Our sailtrack fits into a channel on the mast and is riveted in place. I check the track for loose rivets, especially where two sections join. I also clean the track as I work my way down. We often collect a lot of dirt and grime while in a marina, and Cape Town seems especially prone to it. I use a spray bottle of fresh water and a rag – nothing else. I used to use waxes and lubricants like SailKote, but I found that, while they make the track really slick for a short while, they seem to collect more dirt and gum the track up after a few weeks.

Lights I check all the lights for corrosion, questionable electrical connections and that they actually work. All our mast lights are now sealed LED lights, but when we had non-sealed lights, I opened them all up and checked for corrosion inside. Our tri-color and anchor lights at the top of the mast have an ambient light detector inside, and it is sometimes hard to fool it during the day. It is also difficult to see the LEDs in bright sunlight, so to check that these are working, I wait until dark, then turn them on, and either check them from the jetty or the dinghy.

Spreaders I check the welds and the connection to the mast. I look carefully at the ends where the shrouds contact the  spreaders – a good place for galvanic corrosion to occur.

Furlers In addition to the general checks, I check the sheaves for cracks and the halyards for any chafing. If the upper furler bearings bind, the halyard will wrap around the furler, so I check that the upper swivels move freely. I check that all shackles are properly seized and that any knots look good.

Masthead All the general checks completed,  I then check the VHF antenna for corrosion and looseness, and inspect the wiring and coax connector. I check the wind instrument to make sure it turns freely and is not damaged, and disconnect the electrical connection to check for corrosion on the pins. I check all the masthead sheaves for burrs, and when possible, check that they turn freely.

The time required for all the checks aloft, including the time it takes to clean all the fittings and the sailtrack, is usually 2-3 hours for our double spreader rig. That's a long time to sit in a bosun's chair. I'm usually a little “stove-up” when I finally extract myself from the climbing gear and try walking again. Make sure you wear a hat and have applied lots of sunscreen – and don't forget to pee before going up.

Stay tuned for part 2 for the deck level rigging checks.