Technical Alternator problems?

[Erc1958]

Hi,
I have a 2001 Laika motorhome which sits on a Ducato 2.8JTD chassis. It has developed a problem whereas on starting the engine the alternator is not charging the battery, I have to rev the engine then the alternator begins to supply the approx 14v to the battery. I can then switch over my 3 way fridge in the M/home to battery mode. When I am driving the m/home I can hear the fridge intermittently emit a warning noise meaning the 12v solenoid has clicked off because the alternator isn't supplying the 14v to the battery. My house batteries are connected to a d.c to d.c charger whilst driving and are not otherwise connected to the engine battery. Another thing I have noticed is that there is no battery light or oil light displayed when first turning on the ignition and I am pretty sure there used to be one. This has only happened since I permantly wired in a maintenance charger to my engine battery so it would keep the battery charged when I wasn't using the m/home, although this may be a coincidence. I have tried disconnecting the maintenance charger but the fault hasn't gone. Any help or suggestions would be appreciated, cheers

 

[g8rpi]

Hi,
I have a 2001 Laika motorhome which sits on a Ducato 2.8JTD chassis. It has developed a problem whereas on starting the engine the alternator is not charging the battery, I have to rev the engine then the alternator begins to supply the approx 14v to the battery. I can then switch over my 3 way fridge in the M/home to battery mode. When I am driving the m/home I can hear the fridge intermittently emit a warning noise meaning the 12v solenoid has clicked off because the alternator isn't supplying the 14v to the battery. My house batteries are connected to a d.c to d.c charger whilst driving and are not otherwise connected to the engine battery. Another thing I have noticed is that there is no battery light or oil light displayed when first turning on the ignition and I am pretty sure there used to be one. This has only happened since I permantly wired in a maintenance charger to my engine battery so it would keep the battery charged when I wasn't using the m/home, although this may be a coincidence. I have tried disconnecting the maintenance charger but the fault hasn't gone. Any help or suggestions would be appreciated, cheers

Hi,
I would need more details on what alternator is fitted to the van, but it sounds like your maintenance charger may have damaged the regulator in the alternator. You can normally change these without replacing the whole alternator. Depending on access and space around the alternator you can sometimes doe it without removing alternator.


Robert G8RPI.

 

[corcai]

Before throwing the baby out with the bathwater I would look at any additions to the D+ circuit. If your split chargr dc-dc charger is connected to the alternator D+ it may be overloading it. Also the bulb is part of the D+ circuit in old alternators and required for proper excitation and regulation so if the bulb is blown you can have regulation issues and obvioisly no light.

 

[Erc1958]

Before throwing the baby out with the bathwater I would look at any additions to the D+ circuit. If your split chargr dc-dc charger is connected to the alternator D+ it may be overloading it. Also the bulb is part of the D+ circuit in old alternators and required for proper excitation and regulation so if the bulb is blown you can have regulation issues and obvioisly no light.

OK thanks for that, do yo know how easy/hard the bulb is too change?

 

[g8rpi]

You don't need to change the bulb. Assuming it IS the old type of indicator measure the voltage at the D or IND terminal (the one with a thin wire) with the ignition on and engine not running. If it is less than 6V with NO light on the indicatior circuit may be faulty. Take the wire off the alternator and measure the voltage on the wire. It should be more than 10V with ignition on. Connect a sidelight bulb (5W or so) between the wire and chassis. The dashboard indicator chould come on (sidelight bulb may glow little). Move the bulb's chassis wire to the battry positive, the dashbaord indicator should go out.
If this all works then the indicatorcircuit is OK.

Robert G8RPI.

 

[Erc1958]

OK Robert, thanks for that, I am holiday at the moment so looks like I will have to take it into an auto sparky to have a look at.Cheers,
Regards,
Eric

 

[Erc1958]

Hi Robert, took the vehicle in for repair to an auto sparky. It turned out to be bad connection between the alternator and the dash, all good now, cheers
Eric

 

[g8rpi]

Hi Robert, took the vehicle in for repair to an auto sparky. It turned out to be bad connection between the alternator and the dash, all good now, cheers
Eric

Hi,
Thanks for the update. That would be the IND wire as suspected.


Robert G8RPI.