Week 54 - Electrics 2

Work on the electrics continued with the testing of the installed components. After rigging up the smartcom and relay a couple of weeks ago, these could now be tested to ensure they work correctly. By connecting a multimeter between the relay input (pin 30) and the van chassis (earth) I could determine the voltage reaching the relay - (13.2v with the engine running, 12.3v without).

 
I then adjusted the smartcom with a screwdriver in order to set the point at which the relay would be switched on/off. This would be somewhere between 12.3v and 13.2v in order to charge the leisure batteries when the engine is running and the vehicle starter battery is full, and to turn off when the voltage drops (i.e. when the engine stops running).
 
I tested this using a multimeter between the relay output (pin 87) and the van chassis (earth) - if the multimeter shows 13.2v then the relay is charging the leisure batteries, and if the multimeter shows 0v then it is not. You can also hear and click when the relay switches on and off. Now it is all set and ready to go.
 

Additionally, I fitted a small blue "push-to-make" or "momentary" switch connected to the battery level meter. This switch is used to turn the unit on and check the battery level only as required. Press the switch in to make the circuit and test the battery level, release to break the circuit (hence "push-to make"). The switch was mounted above the battery meter and wired up. A quick test and it works great - job done.