Ok, so I am horrible when it comes to fusing and relays on electrical....here is my issue

I have air ride and a viair 450 compressor, fused at 30A ....I saw alot of kits come with relays but never knew why? Do I have to have one?

Also, I was wondering if a relay will be needed for running a rear battery? I saw you need a relay in between your front and rear batterys to "isolate" them from each other and prevent draining one another...

Any help is appreciated. Thanks!


"Hondas are like tampons, every pussy has one!!!"

David Ortlieb wrote:Ok, so I am horrible when it comes to fusing and relays on electrical....here is my issue

I have air ride and a viair 450 compressor, fused at 30A ....I saw alot of kits come with relays but never knew why? Do I have to have one?

Also, I was wondering if a relay will be needed for running a rear battery? I saw you need a relay in between your front and rear batterys to "isolate" them from each other and prevent draining one another...

Any help is appreciated. Thanks!

Relay can turn a low current line into a high current line. They're nice to use.

You don't need one for the rear battery. They won't drain each other.




Your car may do 13 sec @ 103 mph, but my car does 146db @ 35 hz.

Hmm...mind explaining? I know the internal workings of a relay, and that its pretty much a...i guess you could say automatic switch....I just don't get where they come into helping on alot of things such as the compressor, ect. if they are already on a switched 12V source...it confuses me why they are used for fuel systems,ect. as well...just something that never stuck for some reason


"Hondas are like tampons, every pussy has one!!!"

David Ortlieb wrote:Hmm...mind explaining? I know the internal workings of a relay, and that its pretty much a...i guess you could say automatic switch....I just don't get where they come into helping on alot of things such as the compressor, ect. if they are already on a switched 12V source...it confuses me why they are used for fuel systems,ect. as well...just something that never stuck for some reason

I'll give you a great example. If you have door solenoids and an alarm... the alarm will only put out say 500ma worth of current. I put in relays, fused the relay, and now my 500ma alarm now activates 30 amps worth of door solenoids, each.




Your car may do 13 sec @ 103 mph, but my car does 146db @ 35 hz.

Basically, it allows you to trigger a high current circuit with a low amperage one so you arent pulling 100 amps of current through a circuit rated for 30 amps. You use the 30 amp circuit to activate the relay which turns on the 100 amp circuit.

David Ortlieb wrote:Hmm...mind explaining? I know the internal workings of a relay, and that its pretty much a...i guess you could say automatic switch...

If you know the inner workings of a relay, then you know that the activating circuit never mixes with the circuit that is switched. This allows you to run a high current item switched from a low current circuit. If you did not have relays in your car, you'd have a sh!tload of 10-12 gauge wire running everywhere, because circuits such as a fuel pump, or headlights, etc, would have to have the capacity for the higher current running from the fuse panel, into the interior to the dash switch, and back out to the headlights. Can you picture how thick your wiring harness would be? Also, something like a fuel pump relay is switched by the computer, which runs on very low current. Make some sense now?

Ah, ok...so I think I just wasted money on a switch lol, I have a compressor as stated, fused at 30A, and the switches I had were only good for 20A....could have been solved with a relay couldn't it? Instead of buying a different switch?

How would it run though?

I have np idea what to wire to what tab on the relay...I think it would be in from switch on 87A, then to the compressor on the 30 tab but then with the 2 other tabs I am lost lol


"Hondas are like tampons, every pussy has one!!!"

87 is positive
85 is negative
86 is the power with switch going to the relay
30 goes to the compressor




Your car may do 13 sec @ 103 mph, but my car does 146db @ 35 hz.

oh, ok...so the compressor says max amperage 28A, so it would be fused at 30A...if I just used a 30A 4 prong relay, with a 20A switch...would I just run hot from the battery to the switch, with a 20A fuse between, then off the other side of the switch, through the relay, then through a 30A fuse, then to the compressor??


"Hondas are like tampons, every pussy has one!!!"

A relay only needs about 500mA to turn on. So you would only a 5A or even a 3A fuse between the battery and the switch.

Here

bradsk88 wrote:Here

mad tyte mspaint ftw!



car audio noob since 1984.

Hater's gonna hate

David Ortlieb wrote:Ok, so I am horrible when it comes to fusing and relays on electrical....here is my issue

I have air ride and a viair 450 compressor, fused at 30A ....I saw alot of kits come with relays but never knew why? Do I have to have one?

Also, I was wondering if a relay will be needed for running a rear battery? I saw you need a relay in between your front and rear batterys to "isolate" them from each other and prevent draining one another...

Any help is appreciated. Thanks!

The relay is so you can turn on your Compressor with a Toggle switch and a very small wire (18awg) or so and not have all the current running through the toggle switch itself.

I have 8awg going to my relay, then my Viair is plugged into my relay.

I have a toggle switch that turns on/off constant power to my Pressure switch. The pressure switch then runs to the relay to activate it.


This way, I can shut the system down when I want and not have to listen to the compressors etc.