A few questions about wiring.

[CousinVin]

I am putting an Analog air ride system in my Mk4 jetta and I am having some problems with the wiring, or rather things I am not sure of.

I will be using a Vu4 manifold controlled by an AVS 7 switch box. Where should I route the power to for them, and should it be switched or constant? If switched, wouldn't it be a bit much to ask for that much more power from an existing fuse? ie, wouldn't the fuse blow if i used an existing circuit?

[NegativeCamber]

grab a switched power line and run it through a relay. then you can grab power from a dedicated line from the battery

[KyleAnderson]

Use a switched power source, like the remote turn-on from the head unit, to trip a relay. Use a relay rated for high current, like this:

http://www.parts-express.com/pe/showdetl.cfm?partnumber=075-140

BTW, the .375" spade connectors you need for this can be difficult to find. Some automotive stores will carry them, but not places like Radioshack.

[Oh Damn, it's Sam]

IIRC, a VU4 only draws about 5 amps with four valves open, so a 70A relay is overkill for this application. A standard 30A will be more than sufficient, and they're a lot easier to find. Don't know about the switch box, but I can't imagine a simple switch box draws more than a couple few amps.

[KyleAnderson]

IIRC, a VU4 only draws about 5 amps with four valves open, so a 70A relay is overkill for this application. A standard 30A will be more than sufficient, and they're a lot easier to find. Don't know about the switch box, but I can't imagine a simple switch box draws more than a couple few amps.

I was assuming he would want the compressor on a switched power source as well, in which case a 70A relay would handle the demands of everything. This is how I my system is set up. Of course, there's always more than one way to do things.

[Oh Damn, it's Sam]

Gotcha. But a compressor needs signal both from the ignition of the car, and from a pressure switch, so it should be on a separate relay. If you power the compressor from the same relay as the manifold, it will run all the time, or you'll have to feed all the compressor's power through the pressure switch, which doesn't seem like a good idea to me.

Instead, I'd feed the pressure switch 12V+ from the same relay as the manifold, then when the switch closes, it can trigger a second relay for the compressor. Another commonly-available 30A relay will do the trick for most compressors.

[KyleAnderson]

/\/\

Correct.

I have one main power wire from the battery, which goes to a 70A relay for switched power. From there it splits to each component. The compressor is off a 40A relay from there, triggered by the pressure switch.