Volvo KAMD 42 altenator

[mad_boater]

Anyone had this problem with a Volvo altenator?
When I have been running for about 90 mins the altenator stops charging.When its left to cool down ie overnight it works ok again.Any ideas ?

 

[VicS]

Dodgy regulator or possibly rectifier most likely.

Best bet may be to take along to an automobile electrician who can test and repair as necessary.

It may be difficult to reproduce the fault in the workshop of course.

I assume you have no fancy add on gizmos that could be at fault.

 

[mad_boater]

Dodgy regulator or possibly rectifier most likely.

Best bet may be to take along to an automobile electrician who can test and repair as necessary.

It may be difficult to reproduce the fault in the workshop of course.

I assume you have no fancy add on gizmos that could be at fault.

The batteries it charges are on the domestic side so I suppose there may be items connected that may cause a problem although I have not added anything new other than a bow thruster.I think the auto electrcian is my best bet as you suggested.
Thanks

 

[Who]

Cheap enough just to fit a new one.

I changed both my kad42 alternators in the last 2 years. Only cost about £80 for recon units and they worked perfectly.

 

[VicS]

Fitting a recon unit is sensible.

The price of a new one from VP is €440 !

But if you go to an auto electrician you should get you own back in as good a condition as a recon one perhaps for less doh.

 

[mad_boater]

Anyone had this problem with a Volvo altenator?
When I have been running for about 90 mins the altenator stops charging.When its left to cool down ie overnight it works ok again.Any ideas ?

Before I take the altenator off I wonder if my batteries are causing the problem.I have only had this boat for a year so I don't know how old they are.Could a duff battery or two cause the altenator to stop charging? also what can you use to check the batteries apart from a multimeter.

 

[volvopaul]

Before I take the altenator off I wonder if my batteries are causing the problem.I have only had this boat for a year so I don't know how old they are.Could a duff battery or two cause the altenator to stop charging? also what can you use to check the batteries apart from a multimeter.

A failing battery will make it charge more as the low voltage will make it work harder, id be checking if you have either s plit charger or does the alternator have a double diode pack on it, not sure what engines you have, presume 63ps?

 

[mad_boater]

A failing battery will make it charge more as the low voltage will make it work harder, id be checking if you have either s plit charger or does the alternator have a double diode pack on it, not sure what engines you have, presume 63ps?

I'm not sure about the split or double diodes but I have 2 KAMD 42 on seperate systems.The batteries are the sealed gel type.I just wondered if there might have been some failsafe built in to the altenator to stop it from charging a bad battery possibly causing a fire.Starting from cold it takes a few miniutes at 2-3000 revs then the warning light and buzzer goes on and it stops charging.The rev counter works even when not charging at higher revs but cuts out at tickover.I don't know whats thats all about I thought it ran off the altenator.

 

[volvopaul]

I'm not sure about the split or double diodes but I have 2 KAMD 42 on seperate systems.The batteries are the sealed gel type.I just wondered if there might have been some failsafe built in to the altenator to stop it from charging a bad battery possibly causing a fire.Starting from cold it takes a few miniutes at 2-3000 revs then the warning light and buzzer goes on and it stops charging.The rev counter works even when not charging at higher revs but cuts out at tickover.I don't know whats thats all about I thought it ran off the altenator.

Rev counter does, sounds like brushes.

 

[mad_boater]

Rev counter does, sounds like brushes.

I think removing it and a check at my local auto electric people will be the next step.Thanks again for your help.

 

[volvopaul]

Your often better to test it on the engine as it could be wiring on the engine loom that's faulty before you start removal.

 

[Spi D]

I've had an alternator that stopped charging when the alternator (not the engine) got hot. Appeared to be a diode not stable when temperature went up.

If you leave with an auto electrician remember to tell it is for marine use.

A marinised alternator is not a standard car-part.

 

[VicS]

The fact that the tacho packs up is either a red herring or points to the alternator not generating, as the tacho signal comes directly from one of the stator coils, rather than a rectifier fault. Could be the regulator ( most likely i'd think) or worn brushes.

Makes sense though to check all external connections before removing it.

 

[mad_boater]

I think removing it and a check at my local auto electric people will be the next step.Thanks again for your help.

Took it to a local specialist cost me £25 for a new regulator.Getting some new batteries now as I found 3 of them were duff after buying a battery tester that checks them under load (£20 from ebay).
A result I would say

 

[VicS]

Took it to a local specialist cost me £25 for a new regulator.Getting some new batteries now as I found 3 of them were duff after buying a battery tester that checks them under load (£20 from ebay).
A result I would say

Thanks for the feed back.

Nice to know if a diagnosis turns out to be correct.
Important to learn about things nobody thought of!

 

[mad_boater]

I've had an alternator that stopped charging when the alternator (not the engine) got hot. Appeared to be a diode not stable when temperature went up.

If you leave with an auto electrician remember to tell it is for marine use.

A marinised alternator is not a standard car-part.

Reading your comment about marinised altenator has made me think, has the auto electrician replaced the regulator with a marine one so I rang them and I was told the only difference with automotive as opposed marine is that the casing is insulated not used as the earth.The system I fitted on my 33year old boat was a 'Sterling' one. I had to wire in a replacement regulator that made it charge at maxium untill the batteries were full not like a car one that cuts the charging down within a few minutes to a trickle charge.This is why I wondered if the Volvo ones I have now have that built in them being a much younger boat.I also rang 'Sterling' and was told they didn't have that system fitted by Volvo.
Anyone throw any light on this before I put it back on?

 

[VicS]

Reading your comment about marinised altenator has made me think, has the auto electrician replaced the regulator with a marine one so I rang them and I was told the only difference with automotive as opposed marine is that the casing is insulated not used as the earth.The system I fitted on my 33year old boat was a 'Sterling' one. I had to wire in a replacement regulator that made it charge at maxium untill the batteries were full not like a car one that cuts the charging down within a few minutes to a trickle charge.This is why I wondered if the Volvo ones I have now have that built in them being a much younger boat.I also rang 'Sterling' and was told they didn't have that system fitted by Volvo.
Anyone throw any light on this before I put it back on?

I am not absolutely sure I understand you

BUT

the standard alternator will have a regulator that works just like a car one.

If you want the enhanced charging that you enjoyed on your old boat then you will have to fit " smart" regulator of some description. Sterling is one you could chose but there are a number of others out there.

 

[Spi D]

Reading your comment about marinised altenator has made me think, has the auto electrician replaced the regulator with a marine one so I rang them and I was told the only difference with automotive as opposed marine is that the casing is insulated not used as the earth.The system I fitted on my 33year old boat was a 'Sterling' one. I had to wire in a replacement regulator that made it charge at maxium untill the batteries were full not like a car one that cuts the charging down within a few minutes to a trickle charge.This is why I wondered if the Volvo ones I have now have that built in them being a much younger boat.I also rang 'Sterling' and was told they didn't have that system fitted by Volvo.
Anyone throw any light on this before I put it back on?

Most often the car/marine function is the same. Intelligent charging isn't by defaut fitted to marine alternators and although many engines are fitted with higher output alternators (like in cars because ECU's etc. demand more power), my pointing out referred to the common discussion on marinizing.

Pasted from boatfix.com, FYI:

SOME DIFFERENCES BETWEEN AUTOMOTIVE & MARINE ENGINES

For those of us in the marine industry, a common occurrence is to be questioned by customers about auto vs. marine parts. A common scenario is to have a customer ask for a replacement part for his boat. The part in question is a starter for a 350 cu.in. GM block. You give the customer a price, and he looks at you with a blank look on his face. He, then states (very angrily) "I can get one at the local auto retailer for $29.95".

In the marine industry, this little scenario occurs all the time. Many boaters are unaware of the difference between an automotive and a marine engine and their respective accessories. The most notable differences include the exhaust systems, the cooling systems, the electrical systems, and the fuel systems. Additionally, items such as heads and cams are usually different. For the purpose of this article, we will only be hitting the highlights on select systems.

In regard to the cooling systems, one of the major differences is found in the water-circulating pump. This is especially noticable when you have a raw water cooled engine. Unlike their automotive counterpart, a marine pump works in an open cooling system. This type of system is extremely corrosive to the pump. Therefore, the pump must be altered for longevity. A marine pump has a special ceramic seal, stainless steel backing plate, and a bronze impeller to resist corrosion. An automotive style pump, with its stamped steel impeller, would fail due to corrosion in a short time.

The electrical systems in a marine application are also extremely specialized. In an automobile, any gasoline vapors that accumulate will readily dissipate through the bottom of the engine compartment. However, a boat with its sealed engine compartment, does not have that luxury. Therefore, any spark could literally cause a boat to explode. All electrical components in a boat are either completely sealed or specially vented to prevent such a catastrophe. This includes the starter, alternator, distributor, and many other engine electrical components.

Carburetors typically have what is known in the industry as J type fuel bowls. These allow for the extreme vibration, pitching and yawl experienced on boats. This allows fuel to be drawn in exteme conditions and keeps fuel from being ejected from the carburetor barrels.

Heads and cams are set up for a completly different torque curve. A marine engine must develop most of its torque on the low end of throttle range. This allows for the ability to use a single gear transmition system. Think of it this way:
You get in your car
Start it up
Drive to the highway
Put your foot to the floor and hold it there for an hour
Its a little different, well for most of us.

Although we have only briefly touched on some of the differences between an automotive and marine application; hopefully, it will serve to remind us that there is a difference, and that the reasons for these differences need to be shared with our customers and friends in the boating community. Hopefully, when shared, this information can eliminate some of the "blank stares" in regards to parts, and maybe prevent some dangerious situations.

 

[mad_boater]

I am not absolutely sure I understand you

BUT

the standard alternator will have a regulator that works just like a car one.

If you want the enhanced charging that you enjoyed on your old boat then you will have to fit " smart" regulator of some description. Sterling is one you could chose but there are a number of others out there.

The system then it seems then is the same as a cars.Considering how long these smart chargers have been around its surprising they are not fitted as original equipment at least on the domestic side.I will put the altenator back on and see how I get on with my new 4x110 batteries for the time being.Thanks everyone for your replies.

 

[DAKA]

I'm not sure about the split or double diodes but I have 2 KAMD 42 on seperate systems.The batteries are the sealed gel type.I just wondered if there might have been some failsafe built in to the altenator to stop it from charging a bad battery possibly causing a fire.Starting from cold it takes a few miniutes at 2-3000 revs then the warning light and buzzer goes on and it stops charging.The rev counter works even when not charging at higher revs but cuts out at tickover.I don't know whats thats all about I thought it ran off the altenator.

I have had this issue but its about 8 years ago on Volvo Penta ADAQ41

Alternator went so I replaced with a Car alternator.

The main difference is the car one is earthed by the retaining bolts to the engine.

The marine one is insulated earth.


You need to earth the car alternator to your boat earth.


My first attempt was to a random earth wire I checked with a multimeter.

It worked perfectly for a few minutes and then died.

I had managed to wire it to an earth wire on the exhaust solenoids that turn off after a short running time.

I rewired the alternator to a permanently ignition live earth and it was fine.

You need to check your owners manual as some earths will light up your warning panels if earthed back to your alternator.

choose an ignition live earth wire that has no connections with warning lights or neutral safety switches.

using car parts can be safe and save money but they can also cause problems.