I wanted to add a cooling fan for my DCDC charger in the rear as there's no enough air flow. But I want the cooling fan to run only when the engine is started. One way to do it is to run a normal relay to the fuse box, but I would have to run a long wire. This EasyAs would solve the problem, as it can detect engine alternator running. It does that by checking the voltage rise/drop as well as the voltage ripples from the alternator. However, I now find that when I wire it close to my charger, it doesn't work. When I tested in the engine bay, with the rear DCDC charger connected, it works. When I connect it in the rear, it doesn't work. Initially I thought i could be voltage drop, but I then found when I disconnect negative of my Victron DCDC charger, this relay starts working again. And then when I reconnect the DCDC charger, it still works. So somehow, the DCDC charger is affecting the ignition sensing of my smart relay.
So my question is how do I wire it to have the dcdc charger completely turned off? I find that when the dcdc charger is connected to my cranking battery, it's on as I can connect to the bluetooth. What I want is to have it completely off so that it doesn't affect my smart relay. Then I can use my smart relay to trigger it on.
My charger is DCDC non isolated 12/30
Here's a link to my smart relay: http://www.gsl.com.au/easyas.html
