Jump to content

Vehicle Wiring Regulations for Kits?


Recommended Posts

Afternoon.

Are there any regulations regarding how a car should be wired?

Ie, other than the rate at which things flash, or ensuring fogs can't be turned on on there own is there something that mandates the use of relays in certain situations?

Also when building a one off what are the regulations about the odometer? As far as I can see the discovery 1 '95 speed sensor drives the odometer which ends up being a glorified pulse counter. I can make one easy enough but guess I may need to use one built for purpose?

Cheers,

Wesley

Link to comment
Share on other sites

Exactly what are you talking about: Getting a vehicle through an MOT with altered or additional wiring, passing an SVA/IVA construction & use test for a custom build, selling wiring kits for something to Joe Public, how best to wire something up in your truck, how to work out if you need a relay...?

You can pass an MOT with a completely non-functional speedo as long as they can read the mileage to write it down.

Link to comment
Share on other sites

The two main bits of legislation are:

The Road Vehicles Lighting Regulations 1989

The Road Vehicles (Construction and Use) Regulations

Both as amended

As FF says, which you need to comply with, and any other regulations or standards will be heavily dependent on what you are trying to achieve (other things such as; EMC, individual product standards, type approval (EUWVTA or IVA) etc etc...)

Link to comment
Share on other sites

It's a one off loom for myself. I'm building a kit car based on a Discovery 1. Need to do extensive work on the dash and loom anyway and other than wiring things so they fail safe where possible I wondered if I have free scope to do what I like or not.

While I shouldn't need to pass an IVA I'm building the car to that standard. In part to have a standard to build to, to avoid developer gold plating but to also keep the standard up in areas I may have overlooked.

Link to comment
Share on other sites

I realise I'm getting close to the ban on expressing opinions on the IVA. That's not my intention. I'm looking for information about any legal guides on how the lights, wipers, etc should be wired in a kit build as opposed to what they should do.

Link to comment
Share on other sites

I'm using a discovery loom and removing the bits I don't need for my ibex (mine will be IVA'ed).

IVA etc are only interested in how it's mounted/position and whether it works correctly. They are not interested if it catches fire two weeks later that's your,insurance or the police/courts problem from what I can make out.

Mike

Link to comment
Share on other sites

the vehicle you are stripping should give you clues as to good practice. This coupled with common sense should handle the problem

eg two circuits for either sidelight , so you dont lose all with one problem . relays for high loaded circuits , fuses/circuit breakers for harness protection . all auxillary front lights (other than fog) to go out with operation of dip switch . RVLR will supply what is obligatory . HTSH

Link to comment
Share on other sites

I'm looking for information about any legal guides on how the lights, wipers, etc should be wired in a kit build as opposed to what they should do.

It may be a bit of an obvious suggestion but why not get the manual & do what it says?

Link to comment
Share on other sites

speedo has to be 10% accurate, and can only present a speed higher than the vehicle speed. The rest of the wiring is common sense; on an IVA they do loke at the state of the wiring from a safety point of view. I had a few unused wires in my loom that I just cut off; One point of failure was an exposed wire that might short on the bodywork (it was not live, but still a failure).

Your pulse counter you can replace for a cable setup on a disco box.

Daan

Link to comment
Share on other sites

That's a whole lot of the word IVA in a section of the forum where its not supposed to be mentioned! Just saying...

That's more a rule for where it's unwelcome to whine about the IVA, and since this thread asked specifically about it, I can't see the problem.

Link to comment
Share on other sites

Whoops, cat's out of the bag! I can't see it either. ;-) Look forward to a route through a new resource! Looks like forums number 30 and up need special permission to enter.

Thanks all for the help. I'm now more happy that I haven't missed an obvious technical guide on how things should be done from a technical/schematic view rather than the standard to which the wiring should be finished in the vehicle. I have read through the IVA inspection manual and this covered the securing of the loom and how the lighting and other items like wipers should function.

I'll try and get a copy of the regulations and have a look at the wiring sections. I expect these to be more specific around standard good wiring practice (ie like you'd see in a industrial machines electrical panel) ensuring wires are fuse/breaker protected to prevent them from exceeding their current carrying capacity and IP ratings for electrical switches and enclosures. Perhaps a little detail or guidance in addition to describe the use of seperating ground points for noisey items from communications etc.

Link to comment
Share on other sites

I'll try and get a copy of the regulations and have a look at the wiring sections. I expect these to be more specific around standard good wiring practice (ie like you'd see in a industrial machines electrical panel) ensuring wires are fuse/breaker protected to prevent them from exceeding their current carrying capacity and IP ratings for electrical switches and enclosures. Perhaps a little detail or guidance in addition to describe the use of seperating ground points for noisey items from communications etc.

Think you might be expecting too much from the regs! They're regulations not standards. Doubt you'll find any mention of IP ratings whatsoever. I can't particularly recall seeing them on automotive electrical components either, apart from things specifically marketed as water resistant (e.g. LED Headlamps). As for separate ground points for 'noisy' items - what particularly do you think is noisy? By all accounts a dedicated run straight to the vehicle negative is sensible for CB radios but that's about it.

If I were building a loom from scratch, I'd look at the Td5-era electrical schematics as a starting point, especially if you can lay your hands on a ROW-specification schematic (i.e. TD5 loom but a 300tdi 'clockwork engine). It shows the separate earths, as well as 'standard' colours and, importantly cable cross-sectional areas. This will give you an idea of Land Rover's anticipated current draw for their components. Clearly this was sometimes lacking (lack of headlamp relays being the famous example, routing all the electrons through the headlamp switch). This brings me neatly onto:

As has been alluded to by other posters, I'd try to fit a Disco engine-bay fusebox (you might want to look at a Disco 2 one - it has special connectors but it looks to me like the individual pins are standard 6.3mm spades. As well as a basic fusebox where the 'stock' one is by the gear levers.

Another option might be to look at VWP or Car Builder Solutions' Basic kit car looms they sell. The have, pre-wired, the minimum amount of circuits a kit car builder would need for the basic vehicle functions.

Matt

Link to comment
Share on other sites

Did you link to a secret mod-only forum? ;) Doesn't work for me either.

Well it seems, it's in a admin/mods only area, Sorry guys, I didn't realise it was a 'protected' section, anyway the SVA/IVA manual is here

http://forums.lr4x4.com/index.php?showtopic=31855

http://forums.lr4x4.com/index.php?showtopic=7302

http://forums.lr4x4.com/index.php?showtopic=8579

Link to comment
Share on other sites

I'm not an expert so feel free to ignore me but last time I looked I was sure there is a comment that a kit build car can have an inaccurate speedo as long as it reads faster than the actual speed? Thus they are happy that you will be going slower than the speed limit if you drive with the needle on the correct speed. This is of course flawed in that if you know your speedo reads 30% slower then you will drive faster to compensate. It only works if they don't tell you it reads slower!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy