Poor man's OBA

Good job op been looking to do this myself if i dont go the arb route with the locker in the rear.

 

I'm a little unsure on how the pressure switch is wired in there. Could you clarify?

 

X2. Is the 88P weather-hardened to live under the hood? I have an 85P but I keep it under the rear seat.

Maybe the current draw goes up when the voltage drops? Wonder if the battery or alternator is degrading?

 

Maybe, hopefully it's not an issue with either of those, I've heard of a couple other people talking about their's having issues with the fuse as well so I'm fairly certain it's an issue with the compressor itself.

 

Sorry just seeing this. It's literally spliced in line with the negative lead. Cut negative, wire one lead from switch to one side and the other to the other side. Then mounted in the manifold to get overall system pressure.

 

thanks for the write up bro. did you wire a switch to turn it on inside?

 

I did not. I may in the future, but for now I don't think it's necessary since I have to pop the hood to get to the quick release anyways.

 

Nice write up, it's one of the mods on my wish list. Mine would include a power switch and a tank+regulator to control air bag pressure OTF.

 

Been mounted under the hood for 5 months now, through a very hot SoCal summer. Still works great. Fired it up this morning and added a few lbs to the tires.

 

Gotta ask, doyou cover the air intake for the compressor or no?

 

I didn't, probably not a bad idea though. I'll have to take a look at it.

 

Been awhile since this question was asked but if you haven't found the answer elsewhere here it is.

The pressure switch senses pressure. Below a certain pressure the switch closes(on) and above a certain pressure the switch opens(off). They are available in different on/off ranges you can choose based on what you need air for. Some pressure switches are made with a built in relay to handle the current to the compressor, others don't and are used to energize the activation side of separate relay. A relay is just a fancy switch that allows a small switch current to control a much higher current(more than 3A since that's the limit for most switches). Compressors can draw 30A or more so a relay is definitely in order. The pressure switch threads into the tank or manifold where it can sense the pressure and is wired into the circuit that supplies power to the compressor. High current power is fed from the battery through one fuse to one side of the relay and then to the compressor. Another low current fused power lead goes to the pressure switch and then to the activation side of the relay.

 

Well written and clear.

 

Left out the most important bit, the fuses go at the battery end of the power leads because they protect the wire and need to be between the battery and any possible short circuit.

 

This is great, thanks for the write up!

 

Hey, nice setup! I was wandering if there's a possible way to change the alligator clamps on the viair 450 to an O-ring?

 

You mean ring terminal? Sure, just cut off the alligator clips, slide on some heat shrink, strip the wires, crimp on the ring terminals and heat the shrink tubing. Terminals are sized both by wire gauge and screw/bolt size. #10 by 1/4” for example. Wire gauge should be printed on the wire and you can measure the bolt size. It’s not necessary to get a metric size for this as long as the nuts secure them and they’re not loose.

 

Yeah ring terminals. Would you happen to know which ones to buy to connect to the truck battery?

 

Probably #10 by 5/16” would do but check. A little slop is okay but you want the nut to at least cover the ring hole for good contact. Mine’s a ‘14 5-lug with a 24f battery so things might have changed.