Charge and Sediment warning lights. Again.

[Chris-W]

OK, so these two lights are lit very dimly on tickover, and disappear quite promptly as the revs rise.

From reading the forum I understand that this is more than likely an alternator problem.

My question is this: Considering that the vehicle may have been standing for a while (there's proof of this elsewhere on the vehicle) is it possible that something might just need cleaning? Is it worth investing in some electrical cleaner spray before spending a shed load on a new alternator?

Also, could the battery be at fault? It either isn't holding it's charge (nearly flattened after very light use today) or is that because it isn't being charged fully in the first place.

Cheers

[g8dhe]

Its almost certainly something wrong with the alternator, there is a specific signal from the alternator which feeds the two lamps, nothing else is involved.
the signal is on the link marked 3 which feeds the dashboard lights;

[Chris-W]

Yeah thought so. I'll get a some electrical cleaner on it, check the earths, and check with a multimeter before tackling that though.

Thanks.

[Chris-W]

OK, got a multimeter on it:

Engine off, no load: SB 12.6V LB 11.7v
Engine running, no load: SB 14.1v LB 11.7v
Engine off, lights and fan on full: SB 11.75V LB 11.7v
Engine running, lights and fan on full: SB 13V LB 11.7v

Leisure battery I would say isn't doing anything, but what does the rest mean?

Cheers

Chris

[Simon Jones]

What type of split charger have you got? Some types take a feed to the relay from the alternator which drops the voltage to the point where the lights will glow dimly.

[Chris-W]

What type of split charger have you got? Some types take a feed to the relay from the alternator which drops the voltage to the point where the lights will glow dimly.

I've absolutely no idea mate, I don't even know where it would be or what to look for?

On another note, the two lights indicate an alternator problem, yet the main battery seems to have the correct voltages?

[g8dhe]

Engine off, no load: SB 12.6V LB 11.7v
Engine running, no load: SB 14.1v LB 11.7v
Engine off, lights and fan on full: SB 11.75V LB 11.7v
Engine running, lights and fan on full: SB 13V LB 11.7v

Those are the problem readings, under no load the alternator is just about acceptable, under reasonable load its only just about charging the battery, the alternator hasn't completely failed I suspect just one diode (of the six) has failed so far, but it won't be long especially with cold mornings and lights on meaning more current is required and hence more heat and others will fail within the unit.

At no point has the voltage risen sufficiently to even operate the split charge relay so hence the reason that the L/B has only a partial charge in it.

[Chris-W]

New alternator it is then

[Chris-W]

Well, here's the latest. I bought a decent leisure battery and fitted it in the second battery space. Went to the local Bongo garage to have secondhand alternator fitted. The first thing the guy did was got multimeter out and ran few tests. Straight away he said it was the split charge system. Two seconds later he put three fuses into the split charge wiring that had been removed, and instantly the voltage to the leisure battery jumped to 14 volts. That looks like a result. However, the two dashboard lights are still glowing, well more like pulsating, and so dim they can only be seen at night. More questions to follow.

[Northern Bongolow]

when the leisure gets low because of bad charging, then the charging rate is improved it gives the fuses a spike that can pop them.
the original problem sounds like its still there, the alternator output rate sounds like its up and down. this may take your fuses out again.
did he put a meter on the alternator at all ranges of charge to see if its performing on tickover then when full demand etc.

[Chris-W]

I don't know what he 'exactly' did to be honest.

The leisure battery was fully charged, so little chance of wrecking it, but I'll be able to monitor it's charge state. I would expect the voltage to get less and less as time goes on and it doesn't get enough or any charge.

[Simon Jones]

My thought is that it's just down to the type of split charge that is installed. I made one myself using a relay controlled by a feed from the thin wire on the alternator. It did the job, but the lights glowed dimly. I soon replaced it with a proper kit.

Next time you're around in Salisbury, let me know and I'll take a quick look if you like.

[Chris-W]

Appreciate the offer, thanks. PM sent.