Relay/fuse box

[Dooley]

Anyone know if you can get anything aftermarket like what they basically have in most cars under the bonnet, just a box with a few spots for relays and some fuses, or would it be better just to rip one off a car being wrecked ?

Just want something a bit neater for spotties and that, got too many inline fuses and relays all over the place.

[chimpboy]

I pinched the whole shebang out of a VP, VR, etc Commodore.

It is on the driver's side near the front, holds six fuses and I think 10 standard auto relays, plus five fusible links. And you can get the existing terminals out and solder new cable into them. I also grabbed the steel bracket they mount on (involves bashing three spotwelds with a screwdriver and hammer if you're at a Pick-a-Part type place), then I modified that so it could be bolted into its new home.

This is more than you probably need but it's pretty cool and was cheap. Before I took it to the counter I fully populated it with relays, fusible links, and fuses, so the relays alone were worth more than the $40 they charged for the whole lot. You could leave the fusible links off when you install it and save some space; they are on a separate cover. But there's room for relays to run dual thermo fans, multiple spotties, uprated headlamps, etc and if you can use most of the relay slots then it's very compact.

I think these are a great item for projects; I would probably use one if I was building a buggy or whatever as well.

[-Scott-]

Jason, do you have any pics handy? It sounds like a good idea, I might try to tidy up some of the mods to my DD - I'd like to get an idea of the size of the box, figure out if I have room where I'm thinking.

[murcod]

Google "blueseas", they make them for yachts etc. Not cheap though...

I think Whitwrths sell at least one of their models www.whitworths.com.au

[murcod]

http://bluesea.com/

http://www.bainbridgetechnologies.com/i ... 69&site=v1

[chimpboy]

Jason, do you have any pics handy? It sounds like a good idea, I might try to tidy up some of the mods to my DD - I'd like to get an idea of the size of the box, figure out if I have room where I'm thinking.

I will... remind me if I don't get onto it tomorrow!

[atari4x4]

VN-VP fuse block

[pongo]

VN-VP fuse block

also el falcons have the fuseable links. very nice

[fool_injected]

Jaycar sells these neat Fused Relays
Just something else to consider

They come in various sizes and make for tidy circuits/looms

http://www.jaycar.com.au/productView.as ... BCATID=754

[Jeff80]

This is my set up that I use for lights, compressor etc so I can get at it easily. That is, if you dont mind using your glove box...

[stuee]

Thought I'd dig this up for anyone who has future searches. I'm going to be doing a bit of rewiring soon in the engine bay. I've got to add in some thermos and rewire the headlights with relays. In total only about 5 relays all up. I'm going to be using dual fused relays from traxide (order at the same time as a dual bat controller) and add in a 4 way fuse box for future stuff. So not much in all.

Anyways I'm going to put it in a sealed electronics box similar to these



You can buy these from jaycar and such. Then I'll use grommets to feed the wires in. Im going to use a clear cover so I can see in the case. It offers a nice sealed and neat place to fix all my excess relays and fuses.

I'd say if you have heaps of wiring to do the ex commodore units would probably be best but I'm going to be mounting my spare battery in the rear of the cabin and have a separate fuse box etc in the back for it so there's no need to add more crap to the engine bay.

[Dooley]

Thought I'd dig this up for anyone who has future searches. I'm going to be doing a bit of rewiring soon in the engine bay. I've got to add in some thermos and rewire the headlights with relays. In total only about 5 relays all up. I'm going to be using dual fused relays from traxide (order at the same time as a dual bat controller) and add in a 4 way fuse box for future stuff. So not much in all.

Anyways I'm going to put it in a sealed electronics box similar to these



You can buy these from jaycar and such. Then I'll use grommets to feed the wires in. Im going to use a clear cover so I can see in the case. It offers a nice sealed and neat place to fix all my excess relays and fuses.

I'd say if you have heaps of wiring to do the ex commodore units would probably be best but I'm going to be mounting my spare battery in the rear of the cabin and have a separate fuse box etc in the back for it so there's no need to add more crap to the engine bay.

Well I've gone with an inline 4 fuse box, the one like Jeff80 has in his glovebox, I've got that on a bracket right next to the battery.

I decided to replace some of the dodgy automotive relays, one of mine failed, with some 30A 240VAC/32VDC ones. I was going for something similar to you for the relays, a sealed box with clear lid, I'll use cable glands if I can fit them. Just waiting on a back order from Altronics that I don't think will ever come.

The ones out of a commodore would be great but I don't really have the space and I don't need anywhere near that many... 4 fuses and 2 relays is it.

[stuee]

Well I've gone with an inline 4 fuse box, the one like Jeff80 has in his glovebox, I've got that on a bracket right next to the battery.

I decided to replace some of the dodgy automotive relays, one of mine failed, with some 30A 240VAC/32VDC ones. I was going for something similar to you for the relays, a sealed box with clear lid, I'll use cable glands if I can fit them. Just waiting on a back order from Altronics that I don't think will ever come.

The ones out of a commodore would be great but I don't really have the space and I don't need anywhere near that many... 4 fuses and 2 relays is it.

Well I'm hesitant to depart from using automotive relays. I'm not sure how non-automotive ones would handle the vibrations and heat in an engine bay. In saying that too I'm not using elchepo ones from supercheap and what not. For the single relays I've been using I try to source Hella ones or other high quality brand name ones.

I know what you mean with Altronics though. I had a few bits on back order that just never came. I ended up going in to the store when I had some spare time and picking them out myself. If its something I really need I'll order it from Farnell or RS Australia but then you pay a premium...

[rapid80]

I bought 2 of these, 1 for each battery so the main battery is connected to a solenoid so only powers with ignition on, 2nd battery is constant power for laptop,camp lights etc.
http://www.bussmann.com/pdf/36090f1a-b4 ... f2519d.pdf

5 relays and 10 fuses all in a single waterproof box with a single power feed for the fuses.

[rapid80]

Just add that I fitted circuit breakers instead of fuses so no hassles out bush if something goes wrong.

[stuee]

Well I've built my custom fuse/relay box. 6 fuses, 4 relays. IP65 rated box. Lots of fiddling round in a box that's really too small for what's in there (it was a lot of fun cramming it all in there...). My advice for anyone doing this is get a bigger box than they think they need. The only thing I think I got out of it is that "I" think it looks cool. I've done my best to keep all the wiring color coded for the input signals and outputs from the relays. Truth be told I actually wanted 5 relays in the box but I'm going to cheat and reuse my IPF spotlight relay which has lasted a few engine bay washes and water crossings.

This might give some people an idea of where they wanna go if they're facing a similar problem. Took me probably 5-6 hours to build all up and with all new wiring, relays etc probably around $150. I'd definitely do a lot of things differently next time to make it better.



Excuse the mess but I was working in the spare bed room. Good thing was on the swivel chair I didn't have to get up the whole time except for beer and toilet breaks.

[drivesafe]

Well I wouldn’t call it a mess, far from it.

That’s a nice looking job and I bet you spent a hell of a lot of time getting all the wires to the right lengths.

Good work mate.

[stuee]

Well I wouldn’t call it a mess, far from it.

That’s a nice looking job and I bet you spent a hell of a lot of time getting all the wires to the right lengths.

Good work mate.

I mean the room is a mess . I've got another pic of the whole room which will be in my members thread on AULRO when I finish posting up in that.

Cheers for the comments though. I was lucky in that I only ended up resizing one wire after I finished soldering all the connections on. Got most of them close enough and the heat shrink makes it look nice and neat. I just didn't have big enough h.s to go over the larger white and black wires on the right hand relays.

[+dj_hansen+]

Looks pretty good! 2 questions, is that big power cable big enough to supply all the juice? and how have you bridged the terminals on the fuse block? i have 2 of the fuse blocks in mine, just used a massive soldering iron (200ish watt) and soldered 6b&s to all the terminals

[stuee]

Looks pretty good! 2 questions, is that big power cable big enough to supply all the juice? and how have you bridged the terminals on the fuse block? i have 2 of the fuse blocks in mine, just used a massive soldering iron (200ish watt) and soldered 6b&s to all the terminals

The cable going into the box is rated at 100 amps. Maximum draw if every terminal is drawing max current it 80amps (with high and low beam combined).

The cable is soldered directly to the two terminals that supply the thermofans. The rest are just bridged with blade terminals bent across and soldered. This is the only shonky part of the box that I'm not that happy with atm. But the terminals they are powering don't draw that much current so I'm not to concerned at this stage. The beauty of it is, is that because the box is sealed no wondering debris can find its way to the terminals and short them out, but I still wanna cover them up before it goes in the car.

[drivesafe]

Hi Stuee, Not meaning to criticise but that main cable looks like it’s 8B&S and if so and your powering your lights through it, it’s only rated at about 60 amps, 100 amps.

If it’s only going to be a short run, ( no more that 0.5m ) then it won’t be a problem.

If this is what you are doing, could I suggest that you run another cable of the same size, beside the cable you have.

This would give you added safety and would also make your lights brighter.

[stuee]

Hi Stuee, Not meaning to criticise but that main cable looks like it’s 8B&S and if so and your powering your lights through it, it’s only rated at about 60 amps, 100 amps.

If it’s only going to be a short run, ( no more that 0.5m ) then it won’t be a problem.

If this is what you are doing, could I suggest that you run another cable of the same size, beside the cable you have.

This would give you added safety and would also make your lights brighter.

Well I only say 100amps because that was the rating on the roll that I took it off. It is only a short run but I will take your advice though and run another cable to the box as its a simple task and I have the spare bits needed. Best be safe than sorry (and I'd hate to have worse lighting performance after doing all this )

[Dooley]

Nice work, decided with your opinion and went and got some proper automotive relays. Just picked some Tyco ones up from RS.

I know what you mean about the box being big enough, I got a box that I thought would fit, then realised there wouldn't be enough space to feed my wires through properly due to the lengths of the crimps, except that a bigger box wouldn't fit where I wanted.

In the end I've just gone with a mounting plate for the relays, a bit dodgier than I'd like but going camping today so no choice really...

[killalux]

these are the units i found, very good quality, very similar to factory style boxes. Available to hold 16 blade fuses, or 4 mini relay's, or 7 micro relays. They are italian made and very good quality, with secondary locks to make sure the terminals don't fall out.
They are a little pricey, this setup would be around $200, 32 fuses, 4 mini relay, 7 micro. Come with crimp style terminals so no soldering needed

[stuee]

these are the units i found, very good quality, very similar to factory style boxes. Available to hold 16 blade fuses, or 4 mini relay's, or 7 micro relays. They are italian made and very good quality, with secondary locks to make sure the terminals don't fall out.
They are a little pricey, this setup would be around $200, 32 fuses, 4 mini relay, 7 micro. Come with crimp style terminals so no soldering needed

See the price is the biggest thing that holds me back from purchasing a pre-made unit. If the was a compact unit about that had 4 std automotive type relays (ones that you can pick up from supercheap, auto-one anywhere), 4 fuses, a single power feed for around $60 bucks I'd buy one. $200 is a bit pricey for me, that and getting hold of mini relays can be hard.

I've just installed my box in the engine bay and found even that small box was a prick to mount. No reason you couldn't have all the kit I've got in one block half the size if you were able to manufacture components up from scratch. Hmm, if only I had a bit of spare money and time...

edit: Here it is installed (obviously I've got to finish the wiring... and put the second feed wire in but at least I know it fits in now )

[drivesafe]

Well I only say 100amps because that was the rating on the roll that I took it off. It is only a short run but I will take your advice though and run another cable to the box as its a simple task and I have the spare bits needed. Best be safe than sorry (and I'd hate to have worse lighting performance after doing all this )

Hi stuee, I wasn’t having a go and I was pretty sure you had bought it because it was marked 100amp.

The problem is that here in Australia, cable is rated on it’s 50% cycle rate and to my knowledge, this is the ONLY country that rates automotive cable this way.

Any where else in the world, the cable is rated, based on the safest maximum current the cable can carry in a 100% duty cycle and I’ll explain what the cycle rates are.

8B&S is rated at 145 amps when used in a less than 20% duty cycle application, such as battery to starter motor cable.

The same size cable is rated at 100 amps when used in 50% duty cycle applications, such as powering a fridge, which would normally turn on and off in cycles.

In a 100% duty cycle application, like in a dual battery set up or powering headlights and driving lights ( as in your case ) where the current draw is continuos, the maximum current rate for 8B&S cable is about 65 amps.

If you bought 8B&S cable from anywhere else in the world, it would be marked as 65 amp cable.

It's just a safety tip mate.

[stuee]

Hi stuee, I wasn’t having a go and I was pretty sure you had bought it because it was marked 100amp.

Didn't for a second think you were.

I went to my local auto-one for another run of cable but they didn't have nay at the time (teach me to buy stuff up near the missus house...). Since I'm re wiring my stereo amp to the dual battery in the back when it goes in I was going to use some of the excess cable left after trimming it.

I did measure my cable with callipers and as far as I can tell it is 8B&S.

Question though, does this mean that the 15amp cable I brought for the headlight loom is also 50% dutycycle?

I've already sourced some 25amp stuff for the spotties, but now I'm thinking I might have to do the same for the high beam.

Learn something new everyday... I just wish it didn't cost money haha

[drivesafe]

Hi stuee, the current rating on the cable should be ignored and although this may present a problem if you don’t know what size cable is correct for the job, you are far better off buying cable based on the cable’s Cross Sectional Area of the copper.

This Cross Sectional Area is shown in mm2. 8B&S has a Cross Sectional copper Area of about 7.9mm2.

Now, just to throw a spanner in the works and to show how stuffed the cable sizing is in Australia, here we also have an AUTOMOTIVE cable size, ( again, something that is only used in this country ) which actually has absolutely nothing to do with the Cross Sectional Area of the copper but is based on the Cross Sectional Area of the whole cable including the plastic insulation.

But wait, it gets worse. The AUTOMOTIVE size has no standard for the amount of copper in each size, in other words, you could buy some 6mm AUTO cable with a copper Cross Sectional Area of one size from one company and another brand might have a copper Cross Sectional Area larger or smaller that the one you have.

Back to your question, for headlight, both low and high beam, use 4mm AUTO and for driving lights, use 5mm AUTO.

These sizes will guaranty that you will have a minimum of voltage drop so your lights will run brighter and believe it or not, the globes will last longer.

[Spimon_NH]

Wow, and here I was believing what was written on the package...

Ignoring all the various sizing systems, is there a conventional relationship between current and cross sectional area I could use for an insignificant voltage drop (ie, X mm^2 / amp)?

4mm Auto (allowing 1mm of insulation) powering 100w lights would leave about 0.5mm^2/amp. Sound remotely reasonable?

[drivesafe]

Hi Spimon, there are probably a number of calculators on the web that you can use to work out the voltage drop of cable over a given length ( one is available through the LCOOL web site ) but there is a little more to it and I’ve learnt my trade by hands on experience to the point where I can pretty well select the correct cable size that is needed for most jobs, like the headlight wiring.

I make headlight wiring upgrade kits and these were developed by experimenting ( usually on mates vehicles ) so that I ended up with he best possible results, without costing the world.

This is not a plug for my gear but I have done all the hard work during the development of these kits to get the best results for my customers, to save the customer having to sit down and do loads of math.

Another example, I use 6B&S twin ( 13.5mm2 x 2 ) cable to charge a battery and power a fridge at the same time, in a camper trailer or caravan. You can get better results if you use thicker cable BUT you have to weigh up the additional cost of thicker cable to the actual amount of additional benefit that is going to be gained and in most cases ( not all ) the additional cost is just not warranted.

If you regularly run your trailer battery down to a low start then thicker cable will help charge the battery quicker while you are driving but just how much quicker is another point that needs to be taken into account.

If you do long drives each time your drive from one camp spot to another, the thicker cable is of little advantage.

If you don’t discharge the trailer battery down very much, then again, the thicker cable is of no real advantage.

It’s not just a case of knowing the cable sizes but also understanding the uses.

Anyway, there is a lot more to it but this will give you an idea of whats really involved when selecting cable.