12v comp./relay/pres. switch wiring question...

[blkTJ]

I hooked up my air system and am now rethinking the wiring layout. Please let me know what you think...

The way it is now... power from battery, to fuse, to relay, to pressure switch, to compressor, grounded. Switched power from fuse block, to on/off switch, to relay, grounded.

I'm wondering if it would be better to put the pressure switch in the second circuit. Meaning it would open and close the relay as opposed to being in line with the power to the compressor itself.

Let me know any pros or cons you can think of. Thanks,
Brian.

[mrblaine]

Originally posted by blkTJ
I hooked up my air system and am now rethinking the wiring layout. Please let me know what you think...

The way it is now... power from battery, to fuse, to relay, to pressure switch, to compressor, grounded. Switched power from fuse block, to on/off switch, to relay, grounded.

I'm wondering if it would be better to put the pressure switch in the second circuit. Meaning it would open and close the relay as opposed to being in line with the power to the compressor itself.

Let me know any pros or cons you can think of. Thanks,
Brian.

Yes, you always want the pressure on the trigger side of the relay. Unless it is the big mechanical pressure switch found on most shop compressors, it won't handle the load very long.

Another way to make your relay last longer is to run the power from the battery through the fuse to the compressor. Take the groung from the compressor to the power side of the relay and use that to complete the circuit to ground.

The downside to that is that you have to protect your wiring better, but you should anyway.

[TJRON]

My wiring goes from battery, fuse, pressure switch, cheap on/off switch and compressor to ground.

I have no relays. The switch is actually one of those dinky switches used for alarm systems. It was all I had at the time and I figured it wouldn't last long but it's still working. My point is, The clutch on the compressor takes very little current to operate.

[mrblaine]

Originally posted by TJRON
My wiring goes from battery, fuse, pressure switch, cheap on/off switch and compressor to ground.

I have no relays. The switch is actually one of those dinky switches used for alarm systems. It was all I had at the time and I figured it wouldn't last long but it's still working. My point is, The clutch on the compressor takes very little current to operate.

I didn't read where he was energizing the coil on the compressor clutch through the pressure switch. I did read where he was running a compressor. The little one for my RideRite air bag system draws 17 amps. Will that switch you are using handle that?

[TJRON]

Originally posted by mrblaine
I didn't read where he was energizing the coil on the compressor clutch through the pressure switch. I did read where he was running a compressor. The little one for my RideRite air bag system draws 17 amps. Will that switch you are using handle that?

I have no idea what a RideRite is.
I thought he was talking about the clutch on an a/c air compressor for on board air.
I didn't read it through......
Sorry,
Ron

[blkTJ]

o.k., I can easily move the pres. switch to the other side of the relay. moving the relay to the ground side of the compressor would be a little more involved. I'll look into it this weekend. Thanks for the input. Brian.

...by the way it's a viair comp that draws up to 30 amps.

[Daless2]

Brian, here is a diagram I did a while back that you might find helpful.



There are any number of ways to wires up your compressor and this is only one of them.

+12V goes from the battery, through an appropriate sized fuse, directly to your compressor. As Blaine has recommended, the ground wire from the compressor is connected to pin 30 on a standard Bosch Type Automotive Relay. When the relay coil is activated the compressor ground circuit is completed from relay pin 30 through relay pin 87 to your Jeep?s ground.

The relay ?Coil? is activated via ignition switched +12v.

In order for the compressor to run, ALL of these functions must occur at the same time.

Ignition switch must be on. (Fuse must be good)
In-Cab Compressor on/off switch must be ?On?
Pressure Switch must be ?Closed? (calling for compressed air.)


Hope this helps you out.

Frank

[blkTJ]

thanks... I did it a bit differantly, pressure switch in line with the relay on the hot side of the compressor. everything is rated at 30 amps so I should be o.k. for now. I'll most likely move the pressure switch to the coil side of the relay when I get the motivation. works pretty good though, fills the 2.5 gallon tank to 105 psi in about 1min20sec.

[Scott Evans]

Which model Viair is it?

Scott E.

[blkTJ]

400C. with tank and fittings from Kilby.


FYI... my friends QAII takes over 3 minutes to fill his 2.5 gallon tank. Brian.

[blkTJ]

hey where did this Kia thing come from?????????

[Scott Evans]

Originally posted by blkTJ
400C. with tank and fittings from Kilby.


FYI... my friends QAII takes over 3 minutes to fill his 2.5 gallon tank. Brian.

I have the 400H. It is quiet. Can hardly hear it run over the Jeep motor.

Scott E.