Why relays over fuse?

Just wondering why run relays over putting in an extra fuse box?
Thanks for the help

cheatham wrote:Just wondering why run relays over putting in an extra fuse box?
Thanks for the help

Relays are used so the current going through the switches is small and therefor those switches can last a lot longer; OR those switches can be made less durable and cheaper.

Ok thanks for answering this too.
I may switch to relays, I put a auxiliary fuse box in..

It's a good idea to put a separate fuse box if you are running a lot of accessories on a factory car. You don't cut up the factory wiring and it reduces fire hazard and makes circuits easier to keep up with. Relays need to be fused also and can be used along with the new fuse box if needed.

I got an electric water pump, electric fan, line lock and trans break l gotta supply power to.
My electric fuel pump is wired witha relay.
And a nitrous system but it has a relay too.
Thinking about putting a switch on the line lock as well as activation button..?

The water pump and fan need a relay too. Anything with more than continuous 10 amps gets relays from me. Just keep the wiring safer...

Without relays the switch need to be rated for the amperage draw of the device you're powering. The wire needs to be rated for it too.

With relays, you can use a small 18-20 AWG wire to simply turn on the relay. The coil on most relays only take milliamps to power. The relay does the hard work of routing the heavy current draw through it and to the device.

Thanks for the heads up!!

Another reason is the cheaper switches can fail in the ON position because of too much current passing through it and causing the contacts to weld. Anything over 10A gets a relay for me also and I ALWAYS fuse each circuit. Even the coil circuit on a relay.

HorsinAround wrote:Another reason is the cheaper switches can fail in the ON position because of too much current passing through it and causing the contacts to weld. Anything over 10A gets a relay for me also and I ALWAYS fuse each circuit. Even the coil circuit on a relay.

X2