Blown/ Failing split charge relay system - howto trace fault

[bandario]

Good morning boys and girls. Another day, another gremlin - I must remember to stop feeding the furries after midnight.

Now before anybody starts throwing old threads at me or assuming my alternator is dead I will save some time

I have read all threads related to sediment/ charge light etc etc and can verify a stable, solid reading of 13V at both batteries when off, steady 14.5V when running confirmed by multimeter over the last couple of days; I have even left the multimeter wired onto the alternator and driven around - it seems my alt is functioning perfectly, as expected because it is fairly new.


The situation is this: I have what appears to be a no-name brand solenoid based split charge relay system installed in my van, it was there when I bought it and I know nothing about it or how exactly it is wired but I absolutely love being able to have a fridge for 3 days of camping.

Whilst camping on the weekend I had the bright idea that I could possibly hook a small coffee machine up to our inverter and have a fresh coffee; bad idea. The machine was rated at 1500Watts and I plugged it into a 300W inverter on very thin wiring connected to the rear cigarette socket because I am an idiot.

Nothing set fire and no fuses appear to be blown but I have certainly caused a problem somewhere...thankfully the wife does not read this forum.

Now I am in a situation where the charge + sediment lights are dimly lighting up intermittently whilst driving or idling.

As stated, the leisure battery is still getting reliably charged by the alternator but I have obviously broken something as these lights have never appeared before....now I cannot trust that the leisure battery is going to be the only source of power when camping so I am a nervous nelly.

The lights are not bright or fully lit and they do not stay on, generally just sort of flashing on and off as we go...alarm bells are ringing in my head.

All info points to a fault/ failure in the split charge relay system but I can't find much more information than that anywhere.

Any hints or tips on how to go about addressing this greatly appreciated! The inline fuse is fine.

Also if anyone has any idea if I am able to replace the solenoid type split charge relay with a voltage sensing unit without messing with the wiring???

I can pick up a redarc brand unit for AUD$85 delivered which is a good brand here in Aus but I've no idea on the wiring whatsoever.


Hopefully this post might help a fellow soul who thinks their alternator has gone; I will keep this updated if it turns out to be the case but all signs point to no.

[bandario]

Any thoughts on weather I should be driving the van around in this state? Am I going to cause any further damage?

[Northern Bongolow]

you state that your alternator is new, what is the output of the unit in amps. is the charge dropping when its just ticking over, or pumping out 14v plus all the time.
the reason i am on this track is in the uk we have have been getting (replacements) that are only 70- or 80 amps output, and they are working quite hard and not lasting well.
the gen mazda ones are 90 amp output.

[bandario]

The unit is a refurb - it was done the week before I purchased the van. There is a chance that it is from a Mazda Bravo


Unfortunately my multimeter is a cheap piece of plastic with fixed probes and cannot possibly measure amps that high.

At idle it is providing a consistent 14.4-14.6V at all times; when driving there is some fluctuation depending on revs/ what auxiliaries are switched on but it never drops below about 13.1.


I guess only time will tell if I am right, it is too early for the battery to go flat at this stage but given the reliable voltage readings I remain hopeful.

[g8dhe]

The signal to operate the Charge/Sediment comes directly from the alternator and it isn't used for anything else - so the alternator has to be the most likely culprit. I've not heard of any high discharge situations causing the lamp to come on, but you might try putting as much load on the batteries as possible, headlights on, radio as loud as possible, doors open, internal lights on etc. and see if that causes the two lamps to do anything. Another thing you might check is that the 30 Amp HEAD fuse under the bonnet has good clean contacts, this fuse powers the Head lights but also the field coil for the Alternator if this was causing a voltage drop then that would be likely to cause the charge/sediment light to come on, best to check this before trying the load test above!

[321Away]

I'd try disconnecting the feed for the split charge system and see if the light goes out, i've seen charge/sediment lights come on dim when there is a load placed on the indicator feed from the alternator which some people use as a feed for the split charging system. If the rear socket has stopped working you've probably killed the little fusible link on the back of the lighter socket

Julian

[bandario]

Rear socket is working fine.


I am going to park outside the auto shop this afternoon and replace every fuse in the car if I can get them, they are all looking a little old with some corrosion.


I would absolutely love to take the van in and get the split charge system completely replaced with one that definitely does not touch the alternator but until I am 100% confident the ALT is not going to fail I can't really afford the $ to do that.

Thanks for all the wise advice so far. If my alternator is able to cope with EVERYTHING turned on and still keep the voltage above 13V to the batteries and status of the idiot lights doesn't change I think I will relax a tiny bit. I have seen plenty of threads on here with people saying their charge/sediment lights have been permanently dim since installing split charge relay.

[westonwarrior]

When I had my first bongo and fitted my leisure battery I had the charge and sediment light come on it turned out to be a bad earth on the leisure battery so it was not getting the charge it neeeded so went flat.
My LB was wired to fuse 1 to run the internal lights /radio etc