question Ammeter Reading?

[Sidewinder]

Just wondering what sort of ammeter readings people get off their 430's. My 432 shows a reading but not a massive one, it only moves off the stop a little. 439 shows nothing at all but seeing as it'll only run with the jump leads on I'm sure the alternator isn't putting out a charge to the batteries anyway or if it is there's a wiring fault.

[Tony B]

Have you checked all the drive belts are at the correct tension, I've just had this hassle with a vehicle. So easy to miss.

[sirhc]

The ammeter will only show a reading when you are drawing a current. Switch all the lights on, you should see it move a bit!

[Markheliops]

Mine never moved much on the FV432 - and I never had a problem with batteries.

[Diesel demon]

Ive just fitted a 24v-240v inverter on mine and was paranoid it would drain the batteries...no worries there.

When I start up now I can see the needle move slightly replacing what has been drawn.

 

Just incase anyone else does the same, ensure the invereter is OFF before staring the engine, the surge protection kicks in and everything gets turned off

[andym]

You won't see much movement if it's just topping up the batteries. The ammeter is scaled to show the total output of both alternators (200A) so a trickle charge will only just stir it off the end stop.

 

Andy

[steveo578]

You will only see an ammeter deflection if the batteries are flat and you have had to start the 432 by a jump start.

 

Otherwise as sirhc say turn all the lights (and anything else that pulls current) and it should show an increased reading. But as the batteries sound as though they are near capacity there's probably little wrong with the charging system.

[antar]

Have you checked all the drive belts are at the correct tension, I've just had this hassle with a vehicle. So easy to miss.

 

K60 pack has mechanically driven alternators (2)

[Tony B]

K60 pack has mechanically driven alternators (2)

Lucky you! (Having spent the last two days banging head trying to get a simple alternator belt to work properly:banghead:)

[Sidewinder]

Thanks for that everyone, sounds like theres nothing to worry about too much on the 432.

 

439 might be a different matter though! It'll only start and run with the jumpleads connected, as soon as they're removed the engine dies.. which implies to me with flat batteries that the alternators aren't putting anything out at all to keep the fuel pump running. Or they are and there's a wiring fault.

[andym]

439 might be a different matter though! It'll only start and run with the jumpleads connected, as soon as they're removed the engine dies.. which implies to me with flat batteries that the alternators aren't putting anything out at all to keep the fuel pump running. Or they are and there's a wiring fault.

 

There could be several reasons for that behaviour. I'd be inclined to put a voltmeter across the batteries to check the voltage before and after the engine starts to see just how flat the batteries are and whether or not there's any charging going on.

 

Does the Gen warning light on the driver's switchboard go out when the engine is started, out of interest?

 

Andy

Edited August 10, 2010 by andym

[Tony B]

Sounds like very dead batteries.

[steveo578]

Do the obvious try changing the battery pack from the 432 into the 439 in the first instance -easier than swaping anything else around or doing an in depth wiring check, the fault you describe sounds like a number of failed battery cells at the least (but sometimes the battery can recover by putting it on a bench charger for a day or two)-was the jump just batteries or was it a supplying vehicle under power.

[Sidewinder]

Does the Gen warning light on the driver's switchboard go out when the engine is started, out of interest?

 

 

Yeah, the Gen warning light goes out when the engine is running, it stays lit while the engine is running though if the jump leads are still connected. If I leave the lump leads on with the donor vehicle running for an hour or so before trying to start the 439 then the engine will start and carry on running once the jump leads have been disconnected for 5/10mins before dying, but during this time the Gen light is out.

 

Which to me implies that when the donor vehicle is left charging the 439 batteries for an hour or so it puts enough power in the batteries to keep the fuel pump running for 10mins or so after the jumpleads have been disconnected until the batteries lose power again. Surely if the alternators were putting out power the engine would continue to run? Or would the batteries being completely dead cause this too?

 

Cheers, James (still with a lot to learn about electrics!)

[andym]

OK, that says to me that:

 

 

 

• The batteries are capable of holding a charge (especially if they can turn the engine over on their own after being charged from the donor vehicle)
  
• The FV439 alternators are producing an output, but
  
• The FV439 isn't charging the batteries
  

 

 

For a definitive test, if you've got a voltmeter to hand check the battery voltage when the engine is running and the donor vehicle is disconnected. It should read 28.5V +/- 0.5V with the engine at 2000rpm or above, if it doesn't then you've got a wiring or control box problem of some sort.

 

Andy

[Sidewinder]

Cheers Andy, will dig the voltmeter out the toolbox and have a look next time I'm up.