15 replies to this topic

[Brandon]

After struggling with getting power from the under-hood fusebox into the cabin I've decided to separate things:
"Whole car" stuff runs off that fuse block under the hood.
"In cabin" stuff runs off a different fuse block mounted somewhere.

Question is - where do you tie into key-controlled power to supply enough juice?
From what I've seen, most of the gauge wire used post-keyset will be too small to supply enough amps for more than a couple of circuits.
Unless I'm not understanding how to properly wire a car (entirely possible but I do know you need power & ground regardless to make anything work ) I'm left with knowing a 6-circuit block won't support more than a couple of 20A circuits.

The block I'm using is this one Bussmann Fuse Block - a 15600-series ATC fuse panel. It supports up to 6 30A circuits. Or would you go with their 15300-series terminal & mini-fuse relay found here.

So, where do I pull key-controlled source power from and what gauge wire to I use? I was thinking of using at least a 10GA conductor wire to the input of the panel. From there I run the positive voltage to wherever with a common ground in-cabin for anything I wire to the panel.

Next question: what use is a terminal block? I found one of these behind the radio panel in my car and it was wired with source power coming from the factory in-cabin fuse block into the two non-functioning gauges**. Can it instead be used to support a common ground termination?

Sorry for all the questions. I figure if I can get the simple stuff done myself it saves me money to have the harder stuff (for a shadetree mechanic at least) done by professionals.

Thanks!
Brandon

** This caused me no end of trouble at NJMP-Thunderbolt! Managed to complete less than a lap for qualifying as a stray wire from that terminal block shorted the fuse that ran the PCM! Took Chris W. nearly 2 hours to scope that one out and guess who felt foolish after he asks "Didya check the fuses on the inside?"

[Cy Peake]

I pull keyed power for my data logger from the radio power wire in front of the shifter. I can't remember where I got power for the cool shirt but you want it to work with the car keyed off, when sitting on grid baking.

[wreckerboy]

Perhaps this is overkill, but how about a relay to supply power to your fuse block, and a keyed source controlling the relay? That way, any existing unused in-cabin switched power source could work (such as the radio as suggested above), and you can run a larger gauge feed to the relay from the output of the alternator or some such?

[Brandon]

Wreckerboy - not a bad idea. Keep a "master switch" in-cabin for the secondary fusebox - and make sure it has a light too!
I like that idea!

Plus it gives me an excuse to mount something like those "fire control toggle switches" you see in jet fighter movies.
*big grin*

Off to the hardware store!

[KentCarter]

I have set my car up so the factory stuff runs from the factory fuse panels and all 'extra' stuff runs from a separate fuse panel that comes directly off the kill switch.

[juliancates]

I have set my car up so the factory stuff runs from the factory fuse panels and all 'extra' stuff runs from a separate fuse panel that comes directly off the kill switch.

This is pretty much what I decided to do as well. I only have the IQ3 dash and a few gauges running now, so just used the +12v and ground that orginally went to the instrument cluster, as this was a direct replacement for that anyway. But this is what I will be doing when I end up wiring in the cool suit and any other future accessories, at which point I'll probably move the dash over to this as well.

The nice thing about going right off the kill switch is that there's a nice big lug that you can securely attach a reasonably large gauge wire to in order to run to your new fusebox. Plus, it's inherently controlled by the kill switch, so not "always on".

Match that up with one of these, and you are in business!

http://www.summitrac...arts/MOR-74134/

[Qik Nip]

I just taped into the switched red ~#8 guage wire that comes off the ignitiion switch (and seperately fused) it to power my cool suit and data logger. As suggested above, that tap is switched and has a pilot light to let me know when it's live.
Rick

[wreckerboy]

I powered my cool suit in a similar fashion - ran a ignition switched source to a dash panel mounted switch to a relay by the cool suit. My cool suit is mounted in the trunk, so I ran a larger gauge 12V lead to the relay. From there I ran to a "quick disconnect" (really a flat four trailer connector) to the cooler. Fuses on both hot legs, and the dash mounted switch is lit. I use my ignition switch to shut the car off, never the master kill as I've heard to many stories about repeated use making them unreliable.

This isolates the pump in the cooler and allows me to easily remove the entire cooler set up from the car when not in use. Sounds like a lot of wiring but it really isn't too bad, and my car ('90 1.6) is underweight anyway.

[dstevens]

The relay idea sounds good. I come from the land of starter buttons and no keys. We wire it all to the output of the alt. As for the terminal block, yes you can wire all the grounds to the block then ground the block to a good known point. This ground method is also a best practice in other electrical disciplines.

[TEAM MEDICARE]

I used the feed for the power windows since they're gone. It's right in the console. Plenty of power for cool suit, etc.

[wreckerboy]

There is a good article about this in the current (February 2011) issue of Hemmings Muscle Machines in which they illustrate the installation of a Painless Performance auxiliary fuse panel.

The article does not seem to be up on line yet, but it is the issue with the pretty black/gold GT350H on the cover.

[DonD]

I just bought this from Painless:
http://www.painlessp...archField=70217
Not cheap but high quality and weatherproof. Two relays I'm going run power directly from the battery and trigger one of the relays with a keyed 12v source. The other will be controlled by a switch. Going to clean up all of my wiring and leave some room for new electronics.

-Don

[Brandon]

Alright, going with an 80A relay wired from the main kill switch with a 100A in-line fuse.
I can run the control circuit of the relay off a switched source unless running the switch from the main kill too...
I'll draw-up my diagram and post it shortly for review/critique.

So, to wrap things up, would the 6-circuit block be enough or go ahead and get an 8-circuit one?

Counting what I'd run from the block I come up with 5:
Gauges (4x lighted; H2O pressure, oil pressure, H2O temp, fuel pressure)
Cool suit
DAQ (future)
Radio (future)
Helmet fan (future)

What else am I missing on in-cabin accessories for us racers?

[Muda]

Hey Brandon, with all that capacity you could put in a big amp and some sub woofers.
The only things there that's going to draw any meaningful load are the cool suit and the fan.
Personally, I like to keep the motors and the electronics on separate circuits.

Got to get me one of them water pressure gauges.

[Brandon]

Got to get me one of them water pressure gauges.

A water pressure gauge gets an eye roll? It wasn't necessarily a gauge that was needed but rather something to alert me to the loss of pressure before the temp gets above the "high-temp" alert level.

C'mon Jon, give a brutha some slack!

[Muda]

Ooops, thought that was a smile.

I barely have time to look at my predictive.