15 replies to this topic

[Alberto]

I've been accumulating electrically powered equipment (video, lap timer, cool suit) and have run out of power sources. The video and lap timer are battery powered and always seem to run out of battery during the race. I'm contemplating adding an auxiliary or additional fuse box to power this stuff. Anyone done this before and have a write-up or ideas on how to deal with this?

Thanks.

[Jim Boemler]

Use the stereo fuse, since it's no longer needed, and the wiring already goes to the console. Powering everything from the car is definitely the way to go. You could also use the circuit for the electric windows if your car had them.

[Todd Tagget]

you can also get the add a circuit fuse holders that go into an existing fuse spot. Just remove the old fuse, put in the holder and put the old fuse in that.. then you've got an extra fuse and holder that comes from that..

[Alberto]

Use the stereo fuse, since it's no longer needed, and the wiring already goes to the console. Powering everything from the car is definitely the way to go. You could also use the circuit for the electric windows if your car had them.

Jim, already used the 2 power sources in the stereo area. I need 2-3 more.

Edit - are you saying I can power all of this stuff from that single switched power wire formerly used for the stereo?

you can also get the add a circuit fuse holders that go into an existing fuse spot. Just remove the old fuse, put in the holder and put the old fuse in that.. then you've got an extra fuse and holder that comes from that..

Not sure I know what that is... Got a pic or a link or something?

Electronics is not my strong point... Car is an early 90 base model so no power windows or anything else.


Thanks.

[DionJ]

I think this is the kit I used: http://www.jegs.com/.../70103/10002/-1

[Adax]

I used one of these, a six fuse one.

http://www.summitrac...60091/?rtype=10

Probably switched power from the radio but I don't specifically recall.

[Jim Boemler]

Jim, already used the 2 power sources in the stereo area. I need 2-3 more.

Edit - are you saying I can power all of this stuff from that single switched power wire formerly used for the stereo?

Sure, nothing wrong with powering multiple things off the same fuse. There are two things to think about. First is current draw. The video and lap timer draw virtually nothing, so combining is no problem. The pump will draw more, and I don't know how much, but I doubt it's enough to worry about either (probably less than 2 amps). Bottom line, current probably isn't a concern for this.

The other issue is that if a fuse does blow, everything connected to it will go off. That means that if you combine all your three items on the same fuse, and your pump shorts out, your video and lap timer will also stop working. No damage or anything, but you'll have some dark laps. It's really up to you how conservatively you want to play that possibility.

[Chris Price]

Try something like this: http://www.westmarin...ew#.UGn5Pk0818G

Details at: http://bluesea.com/f..._(2,500 KB).pdf

[Mark McCallister]

Alberto, I have three wire harnesses that run from the switched side of the master switch, one to Traqmate, one to GoPro (using a Garmin harness), one to Coolshirt pump. Each one of those harnesses came with an inline fuse, which I positioned within a foot or so of the master switch, should I ever need to find it (never have). The plus side of wiring the data system directly from the master switch is that (short of throwing the master switch), power is never abruptly lost to the data system (which can be bad for file integrity). Another plus side of doing this way is that none of the wiring is concealed in the dash anywhere. YMMV as always...

[Randy Thieme]

Installed a 6-position fuse box which takes standard automotive blade fuses. Purchased from NAPA. Power comes from the kill switch via a 10-guage wire to a standard 12V automotive relay. Relay is tripped by power from the harness (formerly radio connection I believe). So the whole box is keyed to the ignition switch. Auxiliary instrumentation, data, and transponder take power from it.

Mounted the fuse box and relay socket to a piece of ABS plastic as a mounting plate. The plastic cost a buck or two from the scrap bin at TAP plastics. Tupper-ware like container came from The Container Store and keeps water out during rain races. (And also fingers.)

Overall concept works but it's difficult to find blade fuses < 1 ampere rating. If I had to do it over would research fuses first to find ones which cover the ampere range needed then find a fuse box to match.

[Jim Boemler]

What's the point of fusing the circuit at less than an amp anyway? If you do get a short, it'll draw plenty more, and blow nicely.

[DES4]

What's the point of fusing the circuit at less than an amp anyway? If you do get a short, it'll draw plenty more, and blow nicely.

Protects the component it serves; should there be an output from that component, and that lead shorts out, excessive current can burn out traces on a circuit board... pops them just like a fuse.

[Alberto]

Great info. Thanks gents.

With regards to wiring one of those fuse blocks, do you just source power from the kill switch?

[Randy Thieme]

Yes. In the second photo the yellow wire is a 10-guage wire from the kill switch to the relay (normally open (a.k.a off)). Relay is tripped from the ignition switch. On a humorous note first session out with it got the transponder sign. Remembered to insert a fuse for everything except the transponder. Oops.

[Brandon]

Good job Randy - that's exactly what I was going to recommend you do. Which is what I did myself!

One modification was the inclusion of a separate source feed directly from the battery into a switch/relay. This way I can drain my battery if I feel like leaving it on.
Since my kill switch breaks ground (odd, I know but it still kills "everything" when turned off) I ran the source feed through a 200A breaker (recommended from my the shop that did my tow vehicle stereo install) into a 6-spot fuse box on the tunnel like you have.

My reason for doing it as an independent circuit is it separates accessories from what the car needs to actually run. Should I have a problem with my Traqmate, cool shirt, auxiliary gauges (future helmet fan, whatever else) it means I can still race and not deal with tracking down a non-essential problem.

[Randy Thieme]

Good job Randy - that's exactly what I was going to recommend you do. Which is what I did myself!

Thanks but I can't take credit for it. Actually got the idea from someone else here on the forum but I can't remember who.