Switches, Relays, Wiring

[BeenChevy]

Re-doing some wiring between the battery and interior switches for aux lights. Here's a question about relays that will hopefully save some copper:

Instead of making 3 separate fused runs of wire from each relay to 12v(+) and the additional 3 runs of wire to a ground point - can a guy safely jumper the 12v(+) between the 3 relays to run 1 fused wire to 12v (+) and likewise jumper grounds between the 3 relays as well to make for only 1 run to ground point?

Didn't stumble upon anything online after 30 minutes of searching. Figured a few brilliant minds on here would know what's up with this.

 

[mizzouguy]

I'd be concerned that one individual relayed acc would not draw enough to blow a single large fuse, so if you had to put like a 40 amp fuse to allow all 3 relays to run at the same time, and one of your switched accessories had an issue, it would start doing damage before it blew the fuse.
Id say the ground would be ok though.
Im super ocd though so I would have 3 runs of wire nicely tucked in a run of electrical conduit and color coded lol.

 

[ladorn45]

The other two options you can do is. Run a bigger gauge wire as close to the relays and then tap the relays to that bigger guage wire run and just fuse them. So in theory your saving yourseldf from having to run three seprate wires through out the truck and just one.

 

[BeenChevy]

That makes sense. Might be more trouble than it's worth but nice to tuck things out of the way.

Have a scoche amp dist. block pre-fused with 2-30amp fuses with what looks like 3-4ga-in x 2-8ga-out ?? Think 2 of the ports must be to thread a 4ga completely through. Wish it had 3 out and i'd be set. Anyhow, that could be mounted on the firewall and clean things up a little. Thanks for the knowledge

 

[ScottyBoy]

You can safely do one run of wire. I would do one 12 or 10 gauge wire to the battery or under hood junction block and have a 30 or 40 amp fuse at the battery. Then have a 15 amp fuse on each relay right where the main power wire splits to all three relays. Another good option would be to add an auxiliary fuse block, and have that one main power wire feeding it, then have a separately fused wire coming from that aux block to feed each relay. That would be a lot neater than just splitting the power wire to three fused relays, plus you would have at least one spare circuit to use for any future accessories.

 

[David Paul]

Another good option would be to add an auxiliary fuse block, and have that one main power wire feeding it, then have a separately fused wire coming from that aux block to feed each relay. That would be a lot neater than just splitting the power wire to three fused relays, plus you would have at least one spare circuit to use for any future accessories.

This gets my vote. And it would look very professional. Well at least it could...

 

[nharkey85]

If you need bigger than 10-12awg and space/location allows, get a single stud junction block from amazon and a handful of appropriate ring terminals. I don't like most of the fused junction blocks (car audio style) out there because they don't use ring terminals

You need a fuse near the battery to support the whole possible load, then an appropriate fuse after the junction for each leg.

 

[BeenChevy]

Thanks nharkey85. Just ordered one of these. Planning to draw a 4ga lead fused just off the top batt terminal and will run to the waterproof junction. Running 10ga between the individual fused relays and 14ga inside to the switch panel.

Super clean, easy access.

 

[nharkey85]

No problem. I had been researching a similar setup the compressors on my bagged s10. I needed 4ga input to carry at least 50amps all the way to the back bumper, then split into 2 10ga. I wanted this on a 12v IGN circuit so I had to use a dual batt isolator instead of that single stud. All my connections are rings the way I wanted though