Post by jr on Oct 13, 2019 19:01:40 GMT 10
Had a friend travel with us on our last trip and for them it was a first time to free camp, no power. They had one van battery and no solar so relied on the vehicle to charge there van battery.
On the first night camping the van battery was flat within a few hours. Now this van was purchased new seven years ago and had a seven pin plug and an Anderson plug on delivery.
After some investigation I found the 12V heater in the fridge still switched on even though the fridge was on gas. As we were only stopping for the night the vehicle was left connected on the seven pin plug and the Anderson plug.
I just happened to have the Thetford N604 manual with a circuit diagrams on my computer and found the fridge 12V heater is switched on via a relay with a 30A fuse. Pin 85 on the relay should be energised via the rotary selector switch on the fridge but not in this fridge. This fridge relay pin 85 is wired directly to pin 2 on the van 7 pin plug so while the plug on the van is plugged into the vehicle the relay is energised and the fridge 12V heater is on and power is coming directly from the van battery! Pin 2 on this vehicle is permanently alive and is used to charge the breakaway brake battery.
Just to make things more complicated the Anderson plug feeds to the van battery via a full wave rectifier. They have used two of the diodes in the rectifier to stop the van battery feeding back to the vehicle, not sure why.
The van battery had no chance of being charged as the van battery was wired direct to the fridge and was being supplied from the tow vehicle via diodes so the voltage never got high enough to charge the battery as it was continually having the guts sucked out of it by the fridge.
Removed the relay 30amp fuse and yes ran the fridge on gas continually naughty! That worked.
Does anyone have a Nova Treasure van and how is your fridge wired?
JR
On the first night camping the van battery was flat within a few hours. Now this van was purchased new seven years ago and had a seven pin plug and an Anderson plug on delivery.
After some investigation I found the 12V heater in the fridge still switched on even though the fridge was on gas. As we were only stopping for the night the vehicle was left connected on the seven pin plug and the Anderson plug.
I just happened to have the Thetford N604 manual with a circuit diagrams on my computer and found the fridge 12V heater is switched on via a relay with a 30A fuse. Pin 85 on the relay should be energised via the rotary selector switch on the fridge but not in this fridge. This fridge relay pin 85 is wired directly to pin 2 on the van 7 pin plug so while the plug on the van is plugged into the vehicle the relay is energised and the fridge 12V heater is on and power is coming directly from the van battery! Pin 2 on this vehicle is permanently alive and is used to charge the breakaway brake battery.
Just to make things more complicated the Anderson plug feeds to the van battery via a full wave rectifier. They have used two of the diodes in the rectifier to stop the van battery feeding back to the vehicle, not sure why.
The van battery had no chance of being charged as the van battery was wired direct to the fridge and was being supplied from the tow vehicle via diodes so the voltage never got high enough to charge the battery as it was continually having the guts sucked out of it by the fridge.
Removed the relay 30amp fuse and yes ran the fridge on gas continually naughty! That worked.
Does anyone have a Nova Treasure van and how is your fridge wired?
JR
