Split charge relay gets quite warm: 3 questions

[New Kentish Campers]

1/ As the headline says, my split charge replay is warm to the touch, is this usual? I realise that it's pulling a bit of power through it [just came back from a run where the 'fridge was on the 12v setting] It's a 70 amp one.

2/ I notice that the blue wire from the alternator hasn't been spliced into this relay from the engine end, so I'm presuming that its simply being taking from somewhere at the front of the van/ This is usual on these conversions??

3/ Not exactly related to the split charger, but sort of; I notice that when I flick the 12v fridge power switch that lives on the flat piece of plastic under the heater controls [I think all Holdsworths' are like this] the coolant light on the dash briefly flickers, and then gives a few flashes before staying out. it does this when driving, I've not tried it stationary [only just noticed this]

[California Dreamin]

1/ As the headline says, my split charge replay is warm to the touch, is this usual? I realise that it's pulling a bit of power through it [just came back from a run where the 'fridge was on the 12v setting] It's a 70 amp one.

2/ I notice that the blue wire from the alternator hasn't been spliced into this relay from the engine end, so I'm presuming that its simply being taking from somewhere at the front of the van/ This is usual on these conversions??

3/ Not exactly related to the split charger, but sort of; I notice that when I flick the 12v fridge power switch that lives on the flat piece of plastic under the heater controls [I think all Holdsworths' are like this] the coolant light on the dash briefly flickers, and then gives a few flashes before staying out. it does this when driving, I've not tried it stationary [only just noticed this]

1) No a 70 amp relay shouldn't really get warm.
2) Some people just find an ignition live feed from somewhere at the front, problem is you run the risk of the starter pulling high amount of current through that 70amp relay wired this way.
It really needs to be off the blue exciter so the batteries are NOT connected until the engine is started (you then avoid any possibility of high current being diverted through the relay to the starter).
3) Strange....might be earth related and the live sides are not connected.

Martin

[1664]

2/ I notice that the blue wire from the alternator hasn't been spliced into this relay from the engine end, so I'm presuming that its simply being taking from somewhere at the front of the van/ This is usual on these conversions??

My autohomes relay trigger wire goes to the a spade connection on the back of the fusebox. It registers 12v with the ignition 'on' but drops to 0v during engine cranking so I assume it's the load reduction or 'X' track.

You'd know more about this track Martin presumably?

[bigherb]

Relays do get warm just depends on how warm. There is a set of windings in there which act as a resistor generating heat, common practise to find a relay that is switched on is to feel if it is warm.

Most converters just switched the split charge relay from the ignition even VW did.

[ghost123uk]

I would say "vaguely warm" is OK (but clean up the relay's connectors to be on the safe side, it may be some heat from a poor (likely fridge) connection being conducted into the body of the relay) Q1 = Try it with the fridge off and see if it gets warm then ? - Q2 = does your leisure battery last OK when camping ?

My autohomes relay trigger wire goes to the a spade connection on the back of the fusebox. It registers 12v with the ignition 'on' but drops to 0v during engine cranking so I assume it's the load reduction or 'X' track.

My LeisureDrive is wired this way as well (though not sure if this is original or not of course).

3/ Not exactly related to the split charger, but sort of; I notice that when I flick the 12v fridge power switch that lives on the flat piece of plastic under the heater controls [I think all Holdsworths' are like this] the coolant light on the dash briefly flickers, and then gives a few flashes before staying out. it does this when driving, I've not tried it stationary [only just noticed this]

Ummm, caused by a voltage drop when the fridge heating element switches on, again, likely a bad connection, likely an earth, clean up all connectors on the "crown" behind the fuse box. (Reason = the coolant light is driven be a sensitive box of tricks that looks like a relay on the fuse / relay panel. This item is pretty voltage sensitive)

[nicq]

Your split charge relay should be fused ie 30amp so the Max current you can draw through the relay is 30amps if wired correctly it should not be a problem.

[ghost123uk]

Your split charge relay should be fused ie 30amp so the Max current you can draw through the relay is 30amps if wired correctly it should not be a problem.

Debatable info there (You can easily find 40+ amps (briefly) on start up with a depleted leisure battery)

[nicq]

Your split charge relay should be fused ie 30amp so the Max current you can draw through the relay is 30amps if wired correctly it should not be a problem.

Debatable info there (You can easily find 40+ amps (briefly) on start up with a depleted leisure battery)

I am not disagreeing with you what I am saying if fitted correctly ie fused 30/40 amps you cannot get current high enough to cause overheating the fuse will blow first. As long as the fuse is the same as or smaller than the relay rateing

[New Kentish Campers]

Thank you everyone who has replied

In answer to them:

The relay hangs loose up behind the charger/control box that lives above the wardrobe. When I hold it, when the 12v fridge is selected, it feels warmish, but not hot, certainly not that hot that would instantly tell me something is obviously going wrong. Probably a bad earth/connection'

It is fused at 30 amp too, as suggested. It's cold if the fridge isn't on 12v. Leisure battery is old so I tend to charge it via the control [zig] panel on 240v as this seems to provide a better charge than by relying on the driving charge system. It's a normal car battery too, not a kosher leisure one.

I did clean the earth crowns and tighten them up well when I had the dash out to fix the leaky windscreen and repair the blower fan so I'm pretty confident that they are ok, but will check it over again to make quite sure.

I've got some time time tomorrow afternoon so will check this out some more and let you all know [and the timing issue too, which is on another thread ]

Thanks again, Gents

[New Kentish Campers]

Found the problem The two cables on the fused section of the relay were loose in their crimped connectors. I stripped them back to fresh wire ends, tinned them and fitted new spade connectors. The relay now feels much cooler

[Mocki]

I now have a question for you ( and / anyone else listening) why is your split charge relay connected to your fridge at all?
The fridge should be connected only to the main battery , not the leisure battery , or its third in line to the power!

[nicq]

I now have a question for you ( and / anyone else listening) why is your split charge relay connected to your fridge at all?
The fridge should be connected only to the main battery , not the leisure battery , or its third in line to the power!

Mine is wired to a relay exactly the same as the split charge so it only works when driving. I thought they were all wired like that?

[Mocki]

Yes, my point exactly, it should be connected to a relay that works the same as a split charge, NOT to the split charge relay.

[RedGus]

Your split charge relay should be fused ie 30amp so the Max current you can draw through the relay is 30amps if wired correctly it should not be a problem.

But, didn't the OP say that he had a 70A relay? There wouldn't be much point in having a relay that could cope with your alternator output, then fusing it at half that value. All the split charge relay actually does is allow the two batteries to be connected together as soon as there is charge showing from the alternator. So, if you have one or both batteries heavily discharged (pretty common for the leisure battery after a bit of use), you will potentially be drawing the rated output of the alternator. If you have a 65A alternator, you could well be seeing that current at the battery, so fusing at 30A would mean that you keep blowing fuses for no good reason.

[nicq]

Not really the alt output is 65 amp poss 10 to run engine 55 left split between 2 batts one just started the engine the other run for van leisure chances are it will never blow as both req a good charge.