Permanently wiring an electronic device

TBH if you've not even got a clue where to get power from then pay someone to do it. A car electrics or audio specialist would only charge an hours labour at most to do the job.

Yes it costs you £30-ish but get it wrong and you could end up with a bill for several hundred quid to rewire the melted wiring loom as well as a knackered Satnav.

Nah don't think I'll do that. But even so I would be interested to know what expert fitter guy is likely to do if I had paid him ... if only to satisfy my curiosity.

Excuse me, but these statements seem to be add odds. The satnav will cost a tidy sum will it not? Getting a knowledgeable mate to fit it might only cost you a pint or three. Getting a pro to do it needn't cost more than £20-40 tops.

The simple answer to your question is that the power wiring will be similar to that for any old car audio - if you can't fit a radio then don't bother having a go: something *will* go expensively wrong.

My neighbour put a new radio in his car one afternoon. The next morning we thought that he'd been out overnight and had the windows blacked in an effort to look kule, but no, it'd been gently smouldering away all night and never actually gone bang. Which was lucky, I suppose.

Just a word of warning :)

Si

Hehe. My actual interest in posting this thread was more to gain some knowledge in how the professionals actually go about doing these things. And if it was super simple I'll have a go myself. It seems it isn't super simple so I would settle for a description of how a professional would do it.

I guess all those who are saying "go to a professional" don't know either.

Really? Sure of the polarities of the wires you're connecting? Happy that the method of connection you're going to use isn't going to short out?

Tap off the cig lighter probably.

You've guessed wrong.

There's little point in repeating info that's already out there - you'll find a very good guide in older Haynes manuals about fitting aftermarket radios.

All you're trying to find is a 12v line from the ignition accessory switch, put in a nice fuse to protect your gear and give it a whirl. *You* need to know where to locate your fusebox to tap this out, or a similar place under dash. We can't tell you without knowing what car you've got.

The reason most folk are cagey is that it's pointless telling you if you don't already know how to (a) do basic electrical wiring safely and (b) fit something like a car radio. It really is simple, but dead easy to accidentally short a live wire as you're working - sparks at least - fire at worst.

No I'm not. That's why I "don't think I'll do that"

Well I was hoping for something better than that. I can manage to plug something into there at least ;-)

Ah, no. Conor means, tap off from *behind* the cig lighter, ie its feed cable.

Actually I've a BTEC HND in Electronics Engineering, a City and Guilds in Repair and Servicing of Road Vehicles and also did a short stint at Halfords as an Auto Electrician so yes, I have a clue.

I've also had alot of experience of what can happen when DIYers without sufficient knowledge have a go. For example I remember an Escort that came in because the brake lights didn't work. Opened the fuse box to find a bolt in the holder. Upon further investigation the numpty had fitted a high level brake light, took the feed from the right cluster and when refitting the cluster did an excellent job of sticking a screw right through the twin core cable ensuring a perfect short circuit. Because it kept blowing fuses, instead of seeing what the fault was he kept putting bigger and bigger fuses in until he ended up using a bolt. What he didn't realise was that the entire front to rear wiring loom had now melted into a solid glob of plastic and copper and it cost him £300 for the rewire.

Unfortunately if your experience was indeed gained in the order listed, there must be some risk that your clue fell out, probably as you sat slack-jawed in the Halfrauds service reception waiting on the next mu^h^h punter booking his car in. :-))

Right, we are getting somewhere.

What I don't understand is why they replies couldn't be just describing the work that gets done. Rather than "I've got this qualification and know far more than you but I'm still not going to tell you".

With something like satnav probably dosen`t take much current, so as has been suggested probably a feed taken from some existing wiring within the cabin.

Scotch loks are OK when not abused but the possibilty for bodgemungous dodges is huge, they pierce the insulation on the existing wiring and if forced on to wiring that is too thick for the scotchlok they`ll cut some of the conductor as well.

High power audio amps etc, usually take a feed directly form the battery, with their own wiring led into the cabin direct to the amps.

Whichever way it is done it is important to make sure there is a fuse protecting the wiring downstream of the new connection.

Something that is sometimes forgotten is that while car wiring is low voltage 12V, the available current from the battery is massive, hundreds of amps.

Reminded of that when doing a bit of ,er , modification , slammed the bonnet on a piece of 16mm2 connected directly to battery, bonnet sliced insulation and resulted in a spectacular amount of smoke and the 16mm burnt through like a fuse, heck it was a very graphic reminder of mortality ;-)

Adam

He made it fairly clear what a pro would probably do - take a feed from the rear of the cig lighter (although it was worded slightly ambiguously, hence you thought he meant just plugging it in to the cig lighter).

At the end of the day, a bit of wire needs to be run from wherever you mount the satnav to the rear of the cig lighter (or stereo, or other convenient place to pick up power). The exact work that needs to be done depends on the car and the chosen mounting place for the satnav.

However, unless you're confident of what you're doing (which it doesn't sound like), then it could be a bad idea, because getting it wrong could be an expensive mistake (satnav ain't cheap!).

Cheers

Dave P

Cheers :-)

I suggest you buy a pocket compass from Millets and blue tak it to your dash.

message

Much as I love blu tak, it rates with gaffa tape and cable ties as one of the great instant repairs for anything, tried a compass and body shell must be mildy magnetic `cos North never was the right way.

Adam

I took a feed from the rear of the cigarette lighter to power my boost controller...make sure the lighter is swtiched live though (i.e. only live when the ignition is on) or you risk running the battery down. Other places to take switched live feeds that typically have the wiring to support reasonable drain are electric windows/sunroofs.

..always put a fuse inline though, preferable a low rated one.

RE: Paying someone to do it, I did this the 1st couple of times as I was nervous about doing it myself. Having had the dash apart and done a few jobs myself now I cannot believe I paid money for such a shoddy job. Wires taped together, not using proper connectors etc... will be doing all but the most complex jobs myself from now on.