dis carnect not working

[MidLifeCrisis]

hopefully this is a bit more clear for everyone

Nope !!!

Let's try this from a different angle ....

Split Charge System

You can have one of two types;

A Standard Split Charge Relay.... Which uses a signal from the Alternator to trigger a relay that connects the starter battery positive terminal to the Leisure battery positive terminal.



Or there is the Intelligent Split Charge Relay .... Which uses 'intelligence' to measure the voltage at the Starter battery; when that voltage rises to a level that indicates that the starter battery is being charged by the Alternator, the Intelligent relay will trigger to connect the Starter battery to the Leisure battery.



Now - you should have one of these systems - and it should be wired exactly as per the relevant pic above;

If your split charge system (whichever one it is) is clicking when you connect/disconnect its earth (without the engine running) then the split charge system is faulty - it should only click when the engine is running (as it should only operate when the engine is running);

Maybe we can start with getting that working correctly and see what happens from there (as there seems to be several other problems i.e. fridge earths, fridge operation with headlights etc ...)

[scottbott]

the van is not here at the moment,the split charge is the intelligent type but instructions say,quote "it is essential that the earth to pin 85 is connected directly to the vehicles battery negative terminal for the VSM to function accurately,correctly and precisely.on no account should you splice into another earth cable or make an earth to the bodywork,if you do you will have problems",I have connected it as per the instructions,will try and have alook as the van is in the yard at work and will not be home until the weekend,unless there is anybody in this area that can have a look for me ,a carton of beer or two for some help

[MidLifeCrisis]

Ok - thats all fine with those instructions - but I'd still say that if the intelligent relay clicks when you remove 'its' earth from the battery (with the engine not running) then the system is not working as intended.

Do you have the make/type of the split charge intelligent relay - not heard of VSM??

[MidLifeCrisis]

FYI - the fridge wiring should look like this ...

i.e. the same as a normal split charge circuit but it 'charges' the fridge rather than lesiure battery.

[scottbott]

just had a look around and there s a similar relay to my one and that brand is Nagares,cannot seem to get anything out of the raw components website,do not know if they have ceased trading

[scottbott]

just looking at the Autosleeper wiring diagram and they have terminal 85 going to vehicle ignition switch,a yellow wire,had enough of this for today my head is spinning with this stuff,will probably be dreaming (nightmare) about this

[CJH]

Ok - thats all fine with those instructions - but I'd still say that if the intelligent relay clicks when you remove 'its' earth from the battery (with the engine not running) then the system is not working as intended.

Do you have the make/type of the split charge intelligent relay - not heard of VSM??

If it's an intelligent split charge relay with an adjustable cut-in/cut-out voltage then it's possible that the cut-in voltage has been set too low, so that the raw starter battery voltage is enough to trigger it. In that case then even without the engine running it would connect the two batteries. It would be good to know a bit more about this intelligent relay. Given the wording of the instructions, which refer to "the VSM", I'm guessing VSM might not be the brand, and might stand for something like Voltage Sensing Module.

That wouldn't explain why earthing the fridge stops the disconnect from working though. If anything the low cut-in voltage scenario would imply the opposite, i.e. the fridge power could drop the sensed voltage below the cut-out voltage. But none of this makes much sense at the moment.

From first principles then, if a circuit that is connected to the starter +ve is staying live even when the Dis carnect device is cutting the starter -ve, then:
1) The circuit in question is actually getting a live feed from the leisure battery somehow (which could be caused by the two battery +ves being joined, e.g. through the split charge relay), or
2) The circuit in question is earthing back to the starter -ve via one of the other earth leads. I'm not sure, but I have the impression from Scott's descriptions that the Dis carnect doesn't cut all the earth wires.
@Scott - are there some earth wires that connect directly to the starter battery without going via the Dis carnect?

[CJH]

Given the wording of the instructions, which refer to "the VSM", I'm guessing VSM might not be the brand, and might stand for something like Voltage Sensing Module.

Ah, ok, 'Raw Components' brand. Yes, their website isn't working properly at the moment.

[Tufty_B]

...
I have traced the wires to where they go
...

...
just had a thought that maybe this bloody earth lead may not be anything to do with fridge,though if I disconnect it the indicator light on the MC 2000 control panel does not light up when running on 12 volts
...

This is very confusing, though I do have a question about the above statements.

You have stated that you have traced where the wires go, but then later in the same post state you don't know where an earth wire goes. Am I reading this wrong, or have you made some assumptions in the wiring and does this fridge earth wire also connect to something else along it's length?

[CJH]

That wouldn't explain why earthing the fridge stops the disconnect from working though. If anything the low cut-in voltage scenario would imply the opposite, i.e. the fridge power could drop the sensed voltage below the cut-out voltage. But none of this makes much sense at the moment.

If connecting that mysterious fridge earth wire to the starter -ve is enough to stop the Dis carnect from working, my guess is that the circuit you're trying to cut and the fridge are both earthed to the vehicle body, so that when you connect that fridge earth wire to the starter battery -ve you are completing the circuit. If this is the problem, just connect that fridge earth wire to the disconnected side of the Dis carnect (assuming you need it at all).

[scottbott]

I had the same thought today about connecting the ''rogue'' earth lead to ''the other end'' of the dissconnect to see what would happen,but the van is at work,I usually have the van here to tinker on and my car at work or my car here and the van at work due to space limitations,I am going to try and have them both here at the same time so I can use the car for work and have the van here all the time to work on,I reckon most people have the same problem,not enough space at home,many thanks for the replies so far,I hope this is not going to last much longer!!!