How to properly wire a 12V relay/breaker circuit?

[Silly Seville]

Hey Gang, I feel like I should know this, but even a Bing search doesn't really clear it up for me. So here is the specific question: When wiring a 40 amp DC circuit; which comes first in the circuit after the battery positive, the circuit breaker (a 40 amp auto resetting), or the relay? I am currently running the circuit without any fuse protection at all, and want to put in the circuit breaker. I just don't know where it's supposed to be in the chain. I can't imagine the relay comes first after the battery. But if it does, then I guess that means the switched power leaving the relay goes to the circuit breaker next? OR, does the circuit breaker go into the line that directly feeds the power hungry device? Please help! This is for an aftermarket electric radiator fan setup.

 

[NYBo]

Circuit breaker first.

 

[Silvertip]

Actually, there are two power circuits to consider here. The circuit that activates the relay is a low current circuit so it should have a fuse or breaker before the switch that activates the relay. The high current feed to the relay then has the circuit breaker between the 12 volt source and the relay.

 

[Silly Seville]

Ok, good. That was the direction I was heading. Battery positive-->circuit breaker-->relay-->fan motors.

Silvertip, I did wire the low power switch that signals the relay into the fuse box of the vehicle. I knew that switch needed protected power as well.

Thanks guys!