Alternator battery warning light problems

[Caldy]

Hi my Volvo Penta battery warning light is on continuously when starting. I’ve had the alternator bench tested and is fine. My ford 2712e engine has been overhauled and is back on boat. The warning light wire to alternator is
Brown, is that correct..??? Any advice please.

 

[ST840]

Does it not go out when the revs rise? My battery light comes on every time I start my engine and will stay on until I leave the pontoon and the revs rise, or if I put her in neutral and blip the revs it goes out.

 

[Caldy]

Hi, the light is on continually even on revs.

 

[vas]

does it charge the battery though?

@ST840 had the same on mine, added a resistor after the voltometer battery light and now it turns off 3-4secs after firing up the engine.

 

[Caldy]

Thanks for that, what size of resistor plz

 

[Portofino]

Bad earth somewhere .

 

[Caldy]

Thats a good shout, thanks buddy.

 

[ST840]

does it charge the battery though?

@ST840 had the same on mine, added a resistor after the voltometer battery light and now it turns off 3-4secs after firing up the engine.

Mine charges just fine and only needs around 200 rpm before it turns off. In 3 years it's never caused an issue.

 

[vas]

Mine charges just fine and only needs around 200 rpm before it turns off. In 3 years it's never caused an issue.

same with mine, was charging once you blipped the stick to say 900rpm. The main reason I fixed it was that unless I upped the revs, the annoying VDO beeper would start and you couldn't really stand that!

 

[Caldy]

Alternator has been bench tested and is ok.

 

[vas]

Thanks for that, what size of resistor plz

check first if it's charging
second check wiring as suggested by Porto
then we can discuss resistor. If it was working before, you have to fix what's broken not introduce other "solutions"

 

[vas]

Alternator has been bench tested and is ok.

sorry, alternator bench tested means nothing. Means that it works on the bench. Does it charge the battery(ies) when installed on the boat with the light on permanently?
if not you have a wiring issue to sort!

 

[ST840]

same with mine, was charging once you blipped the stick to say 900rpm. The main reason I fixed it was that unless I upped the revs, the annoying VDO beeper would start and you couldn't really stand that!

Yeah I just switch it off until mooring is slipped.

 

[DavidJ]

I assume your alternator has been tested by a specialist repair shop so if it’s working then it’s working.
Have you had it working properly before?
Even if it’s charging the battery there is still a problem to be solved, what make/model is the alternator? It might be that you have the wrong connection.
Do you have any power going to the alternator at all? Some is needed to initially energise the field.
Photo possibly

 

[BruceK]

Most common faults I have found with the Volvo system that leads to dash and warning light issues

1: The D terminal on the alternator has been incorrectly identified
2: The ignition R/BL line that powers up the dash is loose (although not in your case)
3: The connector to the alarm unit is corroded (although not in your case)
4 The dash loom to engine loom CPC connector is dirty or has bent pins. On mine the cable is too short which allows for it to slowly pull out over time. (right PITA)

 

[Caldy]

T

sorry, alternator bench tested means nothing. Means that it works on the bench. Does it charge the battery(ies) when installed on the boat with the light on permanently?
if not you have a wiring issue to sort!

Thanks to all. I will keep you in the loop, can’t get to my boat due to the usual East of Scotland bad weather. Keep safe

 

[Caldy]

I assume your alternator has been tested by a specialist repair shop so if it’s working then it’s working.
Have you had it working properly before?
Even if it’s charging the battery there is still a problem to be solved, what make/model is the alternator? It might be that you have the wrong connection.
Do you have any power going to the alternator at all? Some is needed to initially energise the field.
Photo possibly

Hi sorry for not replying sooner, it’s a valio and Was tested by a specialist. There are 4 posts pos,neg, w for tachometer and the other for warning light, Ive swapped the signal wires to no avail the pos has two red cables, one from starter the other to instrument panel, the neg post has two, one to the block the other is a return neg from instrument gauges. Thanks for your help. Cheers