One should go in between the lead that goes from the starter battery to the split charge relay and one between the split charge.
Brocott split charge relay wiring diagram.
I have left boxes on the diagram on the left to help you with your measurements.
Instillation guide for a 12v voltage sense split charge relay system thank you for purchasing this kit from simply split charge.
This system uses a heavy duty version of a simple make and break relay the coil of which is energised by a signal that is only 12v when the engine is running usually the charge signal wire from the alternator.
A range of quality voltage sensing split charge relays from 30 amp relays to 150 amp relays.
Most kits will also come with the instructions so you should already have a ruff idea on what needs to be done.
This is how you can install your split charge relay.
The relay will then switch in the alternator feed to the leisure battery to let it charge just like the vehicle starter battery.
This relay is different from other standard split charge relays in that it monitors the main battery voltage and monitors the second battery voltage and only switches the charge to the secondary battery on when required so no over charging can take place and also ensures that the main battery charge is maintained and wont leave you with a flat.
Fit the 2 fuses in the fuse holders.