Ignition sense ?

[LagunaH1]

Hi everyone,

I am working on installing a relay in the circuit which charges my extra battery and runs my radios, compressor etc. The goal is to only power that circuit when ignition is on, and have the circuit be NOT powered when the truck is off in order to limit / prevent drain of the trucks main battery.

I have the relay installed and wired in to the circuit, but I am not sure what my best options are for driving the relay. The relay is mounted near the main battery in the engine bay, so I am wondering if there are any fuses / connections I could tap into to get power when ignition is on.

-As I'm writing this I realize it sounds quite a bit like a n00b question, LOL!

Anyways, if any of you have found a good place to get 12 volts when ignition is on, please let me know

[LagunaH1]

Ha, google is my friend

I have discovered the miracle which is fuse taps.

Sounds like all I need to do is tap into one of the cigar lighter fuses and be done with it

[Colibri]

Another option which I've used in the past to accomplish what you're thinking about is a bluesea magnetic latching automatic charging relay. It senses alternator output.

https://www.bluesea.com/products/catego ... ys/ML-ACRs

[Pit Slave]

The nice thing with the mag sense is if you decide to throw on a battery charger, it will be enough to trip the relay on and charge both batteries at the same time.

Yeah, I smoked 'em, sometimes you just gotta #sendit

[Reloaderguy]

[LagunaH1]

I ended up tapping into F93 (fuse for one of the cigar lighter outlets, which are ignition switched)

All now seems to work well

[FirerescuePW]

Did you fuse the wire at the tap, or are you relying on F93 for overcurrent protection? I ask because you won't put much of a load on the new wire using it to throw a relay. What size is F93?

Sent from my SM-G935P using Tapatalk

[LagunaH1]

I tapped into he fused side of the fuse, so I am relying on the fuse itself. It's a 20A fuse so it should easily be able to drive a relay.