Compressor Wiring

[SCOTI]

My previous truck used just a 'bare bones' approach to air managment & it worked well. The system consisted of a small compressor, 2-gal tank, manual paddle valves, & the bags. The compressor was wired directly into my electrical system (compressor + lead to 1 pole of pressure switch; 2nd pole of pressure switch went directly to the POS batt terminal (30amp fused wire).

While that worked, it allowed the compressor to come on @ any time (not a problem then as I drove the truck daily). My dually will sit around a little more so I was thinking of utilizing a relay so the comp would only be 'hot' when the ignition is on.

I figured I would wire my duallys set-up the same as my previous truck but go through a relay vs. directly to the battery. But, when I researched compressor/relay wiring, most of the set-ups pictured seem to have both the compressor & pressure switch going through the relay.

I'm trying to figure out why both the compressor + & pressure switch would need to go through the relay and/or if my way would work too (knowing there's more than 1 way to utilize a relay).

[Pro Performance]

The keyed side will power the pressure switch, which will trigger the relay as needed, based on pressure. Here is a link to a wiring diagram for hooking up a single compressor.

http://www.azproperformance.com/manu...ng-Diagram.pdf

Dual

http://www.azproperformance.com/manu...ng-Diagram.pdf

[SCOTI]

Yeah, I looked over those diagrams. I guess wired that way the relay is only 'active when the pressure switch triggers. The way I had in mind the ignition switch activates the relay which allows 12v to the pressure switch.

[Pro Performance]

I see... If wired that way, the compressors would kick on right when the key got turned on. The diagrams above, you are correct, the relays is only active when the pressure switch triggers it. This way your load from the compressors is on the relay and not the pressure switch. This will make the pressure switch last longer as well. On the compressor that pull less amps, you can wire through the PS, but I always recommend a relay either way.

Also, on dual compressor setups, I prefer 2 relays to a single large one. This way, if one relays fails, you only lose one compressor and can still air up with the other one working.

[SCOTI]

Ride Techs 'old reliables' (Thomas 327's). That's the way they come set-up from them (pressure switch is threaded into a 'T' fitting off the compressor discharge port).

My plan was to set up the tanks/comps as 2 different loops vs one larger loop but I'm still deciding. 2 pressure switches, 2 separate tanks, & 2 separate relays.

[Pro Performance]

The Thomas compressors are very good compressors, just a little on the slow side, but definitely a reliable compressor as mentioned.

They pull less amps, so they have less strain on the pressure switch. Typically, pressure switches are 30a rated, but always good to relieve load off them whenever possible.

I don't suggest putting the pressure switch at the discharge port, since moisture will build up and cause it to fail early. Many systems are run this way, and work, but my preference is to place the switch elsewhere due to that reason.

[SCOTI]

Originally Posted by Pro Performance

The Thomas compressors are very good compressors, just a little on the slow side, but definitely a reliable compressor as mentioned.

They pull less amps, so they have less strain on the pressure switch. Typically, pressure switches are 30a rated, but always good to relieve load off them whenever possible.

I don't suggest putting the pressure switch at the discharge port, since moisture will build up and cause it to fail early. Many systems are run this way, and work, but my preference is to place the switch elsewhere due to that reason.

Ahh... That makes sense & I hadn't considered the moisture issue. Weird that Ride tech offers (offered?) them that way. I switched to alum tanks this round w/drains just to be able to purge occasionally if desired. I'll reconsider my plumbing/wiring plan....

Also, I like air ride for its adjustability & ride quality. I rarely 'play' so the slower speed & my old school 1/4" airline works just right.