Hey all,

Working on rebuilding my race car wiring. I have a question on relays: Do you use them? I'm guessing that you need them for anything that is a motor (fans, wipers, etc.), but do you use them for things like lights? All the "painless" kits seem to be fused circuits only ... which circuits do you guys run using relays?

Thanks!

I just switches that can hold up huge amperages. Look for industrial rocker/pushbutton switches on Allied Electronics or Digikeys.

Yea, Fans and the mlike cna just be wired right upto a switch, just run it through a circuitbreaker or fuse.

There are many 20A and 30A switches available, even on the shelves at your local auto parts store or Radio Shack. I run 12ga wire to Flexalite 16" fans and a 30A rocker switch, no problems.

Cool ... thanks all!

James would know more than I, but let me add this:
Relays- pro: designed to switch higher current, reliably.
- cons: one more thing to fail, and have to track down.
: one more thing to mount some where.

Switches- pro: easy to swap to identify failure
- cons: fewer choices in style/size when working with high current
versions
: have to be a bit more careful with placement/shielding/joints when
dealing with mounting.

Switches- pro: easy to swap to identify failure
- cons: fewer choices in style/size when working with high current versions
: have to be a bit more careful with placement/shielding/joints when dealing with mounting.

Fewer choices? There are a ton of style/sizes of switches available, maybe not at radioshack, but a computer click away is easier than using gas to get to the store :)

As far as mounting/shielding, not a big deal, just use good connectors, proper soldering/crimping techniques, and its solid.

The biggest factor is using quality electronic components, as the chances of a high quality component failing when used properly is pretty rare. Its when a part is not used properly that a 'gremelin' emerges.

If possible, always try to keep the connectors/breaks down to a minimum. Try to color code/label as much as possible, and always have a wiring diagram to keep record...you never know when you'll have to dig through a harness/connector to find a pin/wire that leads to a failing component.

Its very stressful when you have to go digging into the cars wiring at the track.

Fewer choices? There are a ton of style/sizes of switches available, maybe not at radioshack, but a computer click away is easier than using gas to get to the store :)

As always, Steve J. is spot on.
I suspect he has learnt the same life lessons about having the correct spares trackside.
I know from personal experience that I *hate* having to jerry-rig someone else's faulty electrical work, when all I have access to is RadioShack (or worse) quality switch gear.

Yea, I had to pretty much rewire my entire car when i got it, it had some SKETCHY connections, most of which failed. Including a main ground Crimp-on inline connector that failed and i could not find it b/c it was inside a expandabed nylon sleeve...it took me a couple hours of digging through to find the failed spot.

If you have the ability (basically it takes a decent soldering iron, quality crimp tool, and some misc electronic connectors/wires/etc) and the time, I'd highly suggest being as professoinal as you can with your wiring. Use small brackets and mounts to hold and bundle wires, use zip ties to bundle wires together to nothing is free to swing and catch on something/someone, use heatshrink tubing (the good stuff) where appropriate, and you should eb good to go.

Wiring is pretty relaxing if you do it right. Does not take much physical effort (maybe fishing some lines through can take some acrobatics haha) and if you take a good pace and document all wires/routing, its a fairly easy process. But once you start rushing, or try to cut corners, it'll hurt in the longrun (or potentially short run if something fails quickly).