briwy
Super Poster
VIP Member
Our leisure battery charger recently packed up and I managed to get a second hand replacement. VW wanted just over £400 + VAT for a new one. Identical part number but the yellow wire in the picture was green on the replacement and the numbers after the KW are different.
Everything worked fine charging the leisure batteries but the starter battery wasn't trickle charging. I also found that the 5amp fuse in position 31 under the dash was blowing. This is listed as "Onboard Charger" so was obviously the cause of the problem. Fifth fuse from the right, bottom row, in the picture below. Cutting the green wire on the charger stopped the fuse blowing but no trickle charge to the starter battery. The replacement had come from an earlier Cali which didn't have the trickle charge to the starter battery and must be wired differently.
To get around the problem I have installed one of these units. This takes a 12v supply from the leisure batteries and when they are full it will divert up to a 2amp charge to the starter battery. Very straightforward to install and cost £86. The passenger seat needs to be undone and tilted back (leaving the connections intact) to get access to the wiring.
Black wire goes to Earth, Red wire goes to the 12v live terminal on the leisure battery and the orange wire goes to the right hand terminal (which is the cable from the charge relay to the starter battery) on the black box at the top of the picture. Both the Red and the Orange cables have a 10 amp inline fuse for protection. The unit itself has two 10 amp fuse for polarity protection of the unit and it's circuitry.
I took the charge relay off its mounting plate, removed the plate and cut off a part of it to get better access. Care need to taken doing this and connecting the Orange wire from as the battery cable from the starter battery is obviously live unless you disconnect it from the starter battery.
All now working fine, on hookup the leisure batteries charge first and then when full divert a trickle charge to the starter battery as the the original charger unit did.
When the engine is running the unit disconnects as obviously all the batteries are then being charged from the alternator.
So if you have to replace your charger, which on the later vans charges the starter battery, make sure that the numbers after the KW are the same or you may get the same problem we did. Or, if you have an older van this is a good way for little outlay to get starter battery charging on hookup.
Everything worked fine charging the leisure batteries but the starter battery wasn't trickle charging. I also found that the 5amp fuse in position 31 under the dash was blowing. This is listed as "Onboard Charger" so was obviously the cause of the problem. Fifth fuse from the right, bottom row, in the picture below. Cutting the green wire on the charger stopped the fuse blowing but no trickle charge to the starter battery. The replacement had come from an earlier Cali which didn't have the trickle charge to the starter battery and must be wired differently.
To get around the problem I have installed one of these units. This takes a 12v supply from the leisure batteries and when they are full it will divert up to a 2amp charge to the starter battery. Very straightforward to install and cost £86. The passenger seat needs to be undone and tilted back (leaving the connections intact) to get access to the wiring.
Black wire goes to Earth, Red wire goes to the 12v live terminal on the leisure battery and the orange wire goes to the right hand terminal (which is the cable from the charge relay to the starter battery) on the black box at the top of the picture. Both the Red and the Orange cables have a 10 amp inline fuse for protection. The unit itself has two 10 amp fuse for polarity protection of the unit and it's circuitry.
I took the charge relay off its mounting plate, removed the plate and cut off a part of it to get better access. Care need to taken doing this and connecting the Orange wire from as the battery cable from the starter battery is obviously live unless you disconnect it from the starter battery.
All now working fine, on hookup the leisure batteries charge first and then when full divert a trickle charge to the starter battery as the the original charger unit did.
When the engine is running the unit disconnects as obviously all the batteries are then being charged from the alternator.
So if you have to replace your charger, which on the later vans charges the starter battery, make sure that the numbers after the KW are the same or you may get the same problem we did. Or, if you have an older van this is a good way for little outlay to get starter battery charging on hookup.
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