running 2 compressors of one wire ?

ok also... say its like this... comes striaght off with 8 guage then to a fuse... does it now need to be a 60 amp fuse to have two ten guage wires coming out the other side? or do i need to put a fuse on each one additionally? i already have two 30 amp fuses one the one i have hooked up... one right off the connection.. then one at the very rear of the frame .. ( incase something happens either wya i dont want to try and fish that wire out of the frame along with the other 20 thast runs with it.

im using one long peice of 14gauge is that good? no i ran a 4 gauge to a distribution box with a fuse in the some where i hate those things. that way you can run multiple compressors but use a relay for each

im cofussed by what you just said... im using relays... does the relay work the same as a fuse? i dont get what you saying

no use a fuse and relays or selonoids. they will save your pressure switch

here is how viair would recommend you do it, you run a fused 8 ga min wire to the rear where the comps are, then you purchase 2 viair relay/pressure switches, install them into the tank or somewhere in the main air supply, then you wire up the relay/pressure switches accordingly. now i have installed 2 viair 450s on 1 pressure switch on 2 occasions and had no problem, but the relay is only supposed to handle 40amps max, and the 450s will push out 23 amps max i do believe. i ran 2 viair 400s on one relay/pressureswitch, and they toasted it, but thats drawing a max of 33amps apiece.

Originally posted by Dejavu



no no no .. its coming off the pole on the fuse box where the battery goes to it... youd really have to see it to understand... basically its coming off the battery.

as long as you are on the 0 ga side of that fusebox, ok. If you are still tapping through the fusebox though, it will melt the plastic, the plastic being the weakest link. Trust me, I spent 10 years in car stereo and 4.5 years in school for electrical engineering. I have seen every ghetto way to avoid running wires through a firewall. Dont misundrestand, I'm not saying your way is ghetto, just saying I have seen ghetto work before. If you ran 0 gauge to the fuse box but are still using a fusebox terminal for your compressor tap, big whoop. You are still limited to the current draw capability of the fuse box tap.

For fuses, if you use ONE fuse on the 8 gauge and split it, I would still fuse the two seperately. That way if one compressor takes a crap you wont have to cut wires to remove the short and allow the second compressor to work.

If you dont fuse the 8ga before you split it to two 10 ga, thats ok too, but keep in mind if your splice integrity fails you could have an unfused 8 ga flopping around.

I would fuse the 8 ga near the attachment point, and fuse each 10 ga at the compressor. That way you dont have to crawl under the dash to change individual fuses.

i dont have apressure switch. my overall question is when i run 8 guage out the spot where im connecting theni go to a fuse does it now need to be 60 amp fuse since i will run the two 10 guage wires out the other side of the fuse? theeeeennnn do i need to put a fuse on each compressor after that or are the relays that i have hooked to each one sufficient?

and as far as how to connect them, i'd solder the 3 power wires together.

just do it like i said and bedone with it

Originally posted by bdroppeddak



here is how viair would recommend you do it, you run a fused 8 ga min wire to the rear where the comps are, then you purchase 2 viair relay/pressure switches, install them into the tank or somewhere in the main air supply, then you wire up the relay/pressure switches accordingly. now i have installed 2 viair 450s on 1 pressure switch on 2 occasions and had no problem, but the relay is only supposed to handle 40amps max, and the 450s will push out 23 amps max i do believe. i ran 2 viair 400s on one relay/pressureswitch, and they toasted it, but thats drawing a max of 33amps apiece.

cris you could save a bit of money by using ONE relay/pressure switch and using that to trigger two automotive/bosch type relays. Or use an inexpensive pressure switch without a relay as a low current switch to trigger two automotive/bosch type relays. Might cost a lot less than two pressureswitch/relays.

Or it may not haha. just depends on how much those pressure switch/relay combos cost.