Airbag wiring kit

[kev2809]

im putting together a wiring kit for my bag setup and had a few questions, and also hope other people can use this as a guide when doing their own kit. im using the kit avs sells as a guide here...
http://www.avsontheweb.com/product.p...cat=323&page=1


i wanted to see (mainly price wise) what my own would be compared to them, also i was told by a few people to run a bigger power wire than 10 guage for the compressor.

so far (at a local audio store) i got 2 conductor 16 guage speaker wire (50 feet) for my valves and switch box and 8 guage power wire (20 feet) for the compressor (total - $29). i ordered this relay from suicide doors for $2

[IMG]http://www.*****************/stuff-sale/viair-40-amp-relay[/IMG]

i still need about 20-30 feet of maybe 14 or 16 gauge to ground the compressor, pressure switch, etc.

also still need a fuse holder, and this is where my question comes in. the avs kit sells a 10 guage, 40 amp fuse holder. looking around at local places i see a bunch of similar ones, but the biggest they had is 12 guage with a 30 amp holer. can this kind of fuse holder still be used, or should i try to find one thats bigger? i glanced ebay (summit racing store) and found an 8 guage, 60 amp for about $10 with shipping.


the 8 guage would wire up easy since they are they same, but if i can save a few bucks and still be safe thats good too. any electrical expertise, please chime in

[mullit]

dont use fuses, use manual reset breakers, ebay has the best prices if ya shop around

[kev2809]

whats a manual reset breaker? so the fuse holder avs sells with their kit is not what i need?

[kev2809]

like this..

[tcb-1]

I've use both breakers and inline fuses when I used to install car audio. the shop I installed for preferred the inline fuse just because you have visual reference if your getting juice. I've had breakers stick after a few years on high amp draws. moisture sometimes kill those little guys....

however, both do the trick. I just like the inline fuse.

by the way, did you go with 2 conductor speaker wire?

and last, your running 8 gauge? what compressor are you running? does it have a nameplate that lists amp draw?

[kev2809]

I did buy 16 gauge 2 conductor speaker wire. I bought the 8 gauge because a few people on another forum suggested it. right now I have 1 airlift 450c, but plan on adding another later. I can check the info on it tomorrow morning

[mullit]

when it comes to my air suspension set ups i always try to check the system out before hitting the road, including testing the brakers. It sucks to pop a fuse and be stuck with out a fuse, yeah it happened to me once. **** happens

[kev2809]

I'm not sure how they setup or work..what connects to the 2 posts? and if it "pops", you just reset the button?

[kev2809]

any more input on this guys? i would like to get the rest of the stuff this weekend so i dont have to make any more of those lowes trips lol. also, if i need to, i can order that 8 guage fuse holder if i do that route.

[entourageguy]

power goes thru the breaker. If it shorts it will open the circuit then reset itself. These are really good to use on headlight systems as you don't lose your lights totally.

[kev2809]

so the breaker is a better idea?

what are you other bagged guys input on this? im surprised only 3 guys have chimed in on this

[ruffrida2005]

I would say go with the breaker.

[crakarjax]

You could get that 12 Ga fuse and just take it apart, put 10 gauge wire in it.

Check out monoprice.com for all your wire needs. Lamp cord works well also as a cheaper alternative to speaker wire.

[kev2809]

i guess i could do that..

oh, and i checked the compressor and its 12 volt, max amp of 23. since you need a fuse for each compressor you use, i dont see why the regular 12 gauge 30 amp fuse wouldnt work..right?

[fixit-p]

The circuit breakers are great they have manual and automatic reset but if the condition that tripped the breaker in the first place (short) isn't repaired the breaker will continue to trip and reset like a thermal flasher the best thing IMO is that they have screw terminals instead of blade type which makes for less resistance. Size your fuses according to the components amp draw the compressors probably don't draw more than 20 amps @ 13.8 volts each so a 25 amp breaker will do per compressor, also don't run long grounds to the compressors instead install ground straps to the frame and ground to the frame

[kev2809]

i guess ill go with the 30 amp in line fuse from o reilly. so add 3 bucks to the total. is it ok to wire an 8 gauge to 12 gauge?

[mullit]

Check these out

http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

fuses work too

[crakarjax]

Originally Posted by kev2809

i guess i could do that..

oh, and i checked the compressor and its 12 volt, max amp of 23. since you need a fuse for each compressor you use, i dont see why the regular 12 gauge 30 amp fuse wouldnt work..right?

It will work. In fact, you could go with 14 gauge all around with no problems.

http://www.rbeelectronics.com/wtable.htm

They probably just throw in that low gauge wire to justify the cost.

[fixit-p]

14 ga. is too small, at 30 amps and just 10' of wire the voltage drop is 1.5 volts at 15' it's 2.3 volts (too much resistance) 10 gauge would be better or 12 gauge for short runs.

[kev2809]

thats a cool little chart. im guessing the entire length of my 8 guage will probably be around 10 feet i think. the fuse will be a lot closer to the battery, probably within about 3 feet. so according to the chart, at 12 volts, 23 amps and 10 feet, i can actually go down to 16 gauge...i think. well thats some cool info there.



i guess i can move on to another question. one end of the in line fuse goes to the battery, and the other end to the relay, correct?

[kev2809]

i guess i was typing to slow lol. does it add the entire length of the power cable, or just how far the fuse is from the battery? as in, would it be 3 feet, or 10 feet?

[fixit-p]

I wouldn't go by the chart, it's more important to consider the voltage drop across the entire length of the circuit the best way to explain this is to use the headlamp circuit as an example. Most of us are aware that the stock headlamps on our trucks aren't very bright and because of that a popular mod is the headlamp relay which greatly improves the headlights performance. A 65 watt headlight draws ~ 5.5 amps times 2 equals 11 amps total. According to the chart 20 gauge wire is whats recommended (our trucks have 18 gauge). Just a 10' length of 20 gauge wire at 11 amps will see a voltage drop of 2.3 volts almost a 20% drop. But here's the kicker energy cannot be lost only converted in this case it's converted into heat which further raises the resistance of the wire. So yes bigger is better your compressors will run faster, cooler and draw fewer amps.

[kev2809]

well good thing i have 8 guage lol. i will get the 12 guage and look at it, and if i can i will pull it out and just put my 8 gauge in if i can, but 12 should be good. the 30 amp fuse its self is enough since the compressor only draws a max of 23, right? and also, if the local auto part 12 gauge, 30 amp fuse is max, if i take apart and swap out the 12 gauge with my 8 gauge, can i up the fuse more if i like since im changing the wire?

[crakarjax]

Originally Posted by fixit-p

14 ga. is too small, at 30 amps and just 10' of wire the voltage drop is 1.5 volts at 15' it's 2.3 volts (too much resistance) 10 gauge would be better or 12 gauge for short runs.

Not quite true, for 14 gauge at 10' and 30 amps the voltage drop would be 0.774 volts.

However, since the compressor will never reach 30 amps (peak 23 amps -- probably will happen only upon startup, as the 150psi amperage is actually less than 19 amps) the actual PEAK 10' voltage drop that you can expect with 14ga wire at 10' is about .6volts, at 15' .9 volts. For continuous duty, to voltage drops are .5v and .73v.

source: http://www.stealth316.com/2-wire-resistance.htm

Now, the question here is really, "what is the allowable voltage drop for this compressor?" The part we need to worry about is the DC motor.

So to reiterate what we care about:
- MAX 19 amp continuous
- MAX 15' wire run
= .73v drop at 14 AWG
= .3v drop at 10 AWG

So yes, you will end up having a .4v increase in voltage at the compressor with 10AWG vs 14AWG. The difference is a 2.5% voltage drop vs. 6% voltage drop. Typically 6% is acceptable and that's why 14AWG is acceptable -- keep in mind this is a 15' run, which is really not going to happen. I will probably go with 12AWG myself, since 12 gauge speaker wire is very readily available, and I have a 150' spool left over from wiring my home theater speakers.

[fixit-p]

I used the calculator on here yesterday http://www.powerstream.com/Wire_Size.htm it was linked in this thread yesterday but not today. I don't know what assumptions went into the calculator but according to ohms law your figures are correct but either way it still confirms that bigger is better 6% as opposed to 2.5% voltage loss