Alternator problem?

[snowleopard]

One of my alternators is only producing 13v and the charge light is on dimly. The other gives 14v and they are both controlled by the same adverc regulator.

I think it may be down to bad contacts somewhere but can anyone explain what's going on so I know where to start looking?

Thanks

 

[William_H]

Hello Chris i don't know much about the adverc regulator system when using 2 alternators however. Here are some thoughts. You should check the drive belt first. I am sure you have done that. you should check likely wiring problems. Terminals etc. on my half boat I run a power wire under the carpet in the cabin. Twice now I have had corrosion mid wire presum,ably the insulation was damaged by someone stepping on it so don't trust wiring runs.
it may be possible to extend wiring of the output and field wires so that the alternators can be swapped over. Or they could be physically interchanged. however if you remove the alternator a check of the brushes and slip ring is worth while. They are usually mounted ina box on the end opposite the drive pulley with 2 small screws.( the box often contains the original regulator) removing the screws enables you to pull the box away with the brushes attached. you will see how these bear onto the slip rings and carry current to the rotating field coil. The rings should be shiny and reasonably smooth. Noticeable wear is often ok. usually any real distress will be obvious. unless there is a diode failure which is unusual the brushes are the only problem likely in the alternator. You could then swap them over or get it checked by a car electrics overhaul specialist.
The problem may be in the adverc or it's wiring. it may be practical to revert to the original regulator with a wire from the battery via a small lamp to the regulator terminal and another wire preferably with an ampmeter in series from the output to the battery. This stand alone with one battery arrangement should charge happily if the alternator is good.
good luck and persevere. regards olewill

 

[boatmike]

I doubt if the alternators themselves are at fault. Usually the failures you get with them cause them to fail completely, but you can only really check brushes or diodes anyway which means stripping them down so I would leave this until you have checked other things. I have never run two alternators from one smart charger and know the sterling better than the Adverc (on my boat have one for each engine) but would have thought the first thing to do would be to disconnect the battery + wire from the Adverc and let both alternators revert to "normal" charging. If the problem goes away then it's probably the wiring from the adverc to the alternator as logic would suggest that if the adverc were faulty both would be duff. If the problem persists its probably the "normal" wiring or connections to the alternator and you need to look at each in turn.
2 other thoughts. Are you operating with one starter battery for both engines or 2? If 2 then look at the sensor wire from the adverc to the battery. You should have one to each. If this is faulty it might be the problem. If only one battery forget it.
Also don't forget that the fault might not be at the alternator end. It might be a duff connection or a fault in the engine instrument panel. I have known quite a number of the warning light circuits to fail giving just this problem. Bloody manufacturers increasingly insist on using PC boards or encapsulated electronics for this nowdays rather than good old fashioned wiring and they suck. If they are both the same I would try swapping over the plugs at the back of the instrument panel to see if the problem stays on the same side or is associated with the panel. At least you will eliminate the problems one by one that way and if all else fails you could even swap the alternators over. If it really is the alternator itself this will expose it.
Sorry if thats all a bit obvious but it's sure to to be something obvious once you find it, it's a process of eliminating the easiest faults first!

 

[halcyon]

Typical of a diode gone, two phases are charging, one is not, so warning light is pulsed, and appears dim.
If you can get alternator out easly, get it checked, then you have an answer one way or the other.


Brian

 

[boatmike]

Yes it could be that but it could also be lots of other things as well. The main object of diagnosis is to determine the sickness before operating on the patient!

 

[halcyon]

The first object in life is to start at a known point and work your way through.
At the moment we have a fault and a common reason for the fault, it is easy to check, if you can say the alternator is ok. Then you can start at the alternator and work out, at the moment you (a royal you ) can have a fault anywere on the boat, which you could spend days going round.

Brian

 

[boatmike]

I don't wish to argue, but it would take no more than an hour to eliminate the adverc and any panel and wiring faults before assuming that it is the alternator and removing and stripping that down only to find there is nothing wrong with it. But hey you are entitled to your opinion! You might indeed as I said in the first place be quite right in your diagnosis but I always try to avoid mending things that ain't broke if I can.....

 

[snowleopard]

My setup uses a separate starter battery for each engine with a split charge diode feeding the house banks from either or both engines. The battery sense wire from the Adverc goes to the house bank.

I'm looking for easy things I can try before taking bits off. I'll try unplugging the Adverc to revert to internal regulation. It's not easy to swap harnesses round owing to the position of cable runs. I would have suspected the control wire connection from the adverc to the duff alternator but for the warning light.

When I've had a dim ignition light on a car in the past it's always been alternator diodes but the fact that I still have 7A of charge going into the battery from that engine means it can't be a total diode failure.

I recall someone on this site talking about how the charge light is activated and the effect a dirty terminal can have. Unfortunately it has dropped below the search facility's horizon.

Thanks guys.

 

[steve28]

With my charge controller (sterling) i can disconect it from the alternator thus reverting back to the original regulator/charging system. To do this i disconnect the field wire.
It should be noted that haylcon has had many years of marine electronics experience, at the end of the day its all advice and most forum users will seek a professional company in the end anyway.

steve

 

[salamicollie]

Snowleopard, I've got an Adverc but a single alternator system - 2 suggestions

1. try unplugging the control loom from the Adverc without the engine running! - this forces the alternators to drop back to their in bult regulator. IF you still get thesame effect -> not the Adverc

2. Ring the guys at Adverc, they are usually very helpful 01902 380494

 

[boatmike]

The fact that you are getting 7 amp charge makes me think more and more that it MAY be the warning light energising circuit itself. If you can't swap the leads over easily can you take the panels out and reverse them to eliminate the control panel being at fault? One very common point where things go wrong is where the cable loom is "plugged" into the engine. The plugs used are very seldom waterproof and often hang together on corroded terminals without anyone knowing..... I always eliminate these plugs on my boats and hardwire the panel to the engine directly as I have seen so many of them disintegrate. It's worth just unplugging this and examining the terminals before you go any further. It's such an easy thing to miss! Either way you are looking for a good connection between the terminal on the alternator and the light circuit itself at the panel. The fact that you have 7 amps charge but the light is still on, even dimly, would make me look for a poor connection in this wire which could just be in that infernal plug. Why not take a length of wire direct between these points and "jump" everything else? If the light goes out and the charge rate goes up theres your problem.... Again easy enough to do......