square d press. switch

Edited: 9/3/2006 4:11:47 PM by fnf150

correct me if im wrong, but i believe there are 4 posts on the square D, two on the left and two on the right being paired together, got a power wire running from the battery to a relay and from the relay to the far left post, and then from the second post on the left to the compressor, then vice versa for the other compressor, each compressor should have its own power wire from the battery, its own relay, and its own side on the pressure switch, so 2 compressors = 4 leads to the pressure switch, 2 for each compressor

Originally posted by 1twztdwagon



http://www.airridetalk.com/images/stories/wiring/1_1_1.gif in this picture only one side is hooked up i have 2 compr. do i only need to hook them up to one side ? what if i fused the switch an just ran it straight to the batt instead of jus running it to the ign wire..

Its not necessary to use both sides of the square D pressure switch, but you can do it if you really want to. The way I have it diagramed simplifies wiring.

The issue with running a wire from the pressure switch straight to the battery, rather than through a switched source like the ignition is that the compressors CAN come on at any time, regardless of if your vehicle is running or not. By putting it on a switched source (I use the ignition in my pictures simply because it takes any guess work out of the equation and requires no thought from the user), the compressor can only run with the circuit is activated. The ignition switch requires no user interaction and prevents the compressors from coming on when your vehicle is off (which would drain any battery in no time).

how many amps is that pressure switch rated at,cause i cant find one that will last

Originally posted by dirkbelt



how many amps is that pressure switch rated at,cause i cant find one that will last The reason that relays are used is so that a pressure switch doesn't need to have an amp rating. A relay will pull less than 1 amp, which any pressure switch can handle, whereas a compressor pulls upwards of 20-40 amps, which a pressure switch cannot handle.

yea but it frys relays 2

air ride talk an bagginit have the same set up except one say to wire L1 to the selonoids an T1 to a acess. an vise versa for the other site which one is it ? also when i fuse the 80 amp selnoids should i run like a 100 amp fuse for each ?

Originally posted by 1twztdwagon



air ride talk an bagginit have the same set up except one say to wire L1 to the selonoids an T1 to a acess. an vise versa for the other site which one is it ? also when i fuse the 80 amp selnoids should i run like a 100 amp fuse for each ?

Use the one from AirRideTalk, it is the current one. When I made the ones on bagginit, they were done incorrectly, and since I no longer have access to the website, nor do I care to have it, the images cannot be changed by me.

(but if you want to get technical, it really doesn't matter which lead goes to the ignition and which goes to the relay)

Edited: 9/5/2006 1:01:13 PM by 1twztdwagon

can i hook one selenoid up to each side?

yes, you can hook each relay up to each side.

From what I have seen, the square-D pressure switch is meant to work with residential and commercial wiring. so amps are not an issue. I have never seen using a relay as an option. Relays suck ass anyway. You need a continuous duty solenoid from the auto parts store. Napa Auto parts #ST95 It is 100% duty and will never burn up if wired correctly.