Is this a good idea?

Post by **johnpaul74** » Tue Jul 03, 2007 7:18 pm

I was thinking of adding a few extra electrical thingies like a ciggy lighter and a few clocks and that. being something of a novice I don't really fancy chopping into the existing wiring. Saw these on the Maplin site. Was thinking of piling them all on the pozzie and negging to earth anywhere. What do you reckon?

<img src=http://www.maplin.co.uk/images/300/wd15r.jpg>

Post by **rayofleamington** » Tue Jul 03, 2007 7:55 pm

There's normally an easy place to tap off - the fuse box on the bulkhead. You need to consider if you want these permanently live or not. Generally 'not permanently live' is prefferable but try to avoid anything with a lot of current draw, otherwise wire and fuse them from the battery - to make it a switched live you'd then need a relay.
A normal car stereo itself is not a big problem - unless it's very powerful or you plan to leave it on when not driving. If you add a lot of current consumers, then the dynamo will be less likely to keep up. Over winter you'll find a dodgy battery goes flat quite quickly as it's not getting much charge. A decent battery will last longer but trickle charging it once or twice over winter can help a lot.

Alternators are an obvious choice if you want to add loads of ICE, however they are less reliable than alternators (especially if not disconnected when your car gets welded...).

Post by **bmcecosse** » Tue Jul 03, 2007 9:56 pm

Yes - you MUST unplug (no need to remove) an alternator when any electric welding is taking place on the car body.
Any accessories should be fused to minimise fire risk!

Post by **Matt** » Tue Jul 03, 2007 11:37 pm

surely you mean alternators are less reliable than dynamos Ray? ;)

Post by **Peetee** » Wed Jul 04, 2007 8:02 am

This is what i did:

The brown wire goes to the live terminal with a O crimped end behind the terminal clamp bolt.

Post by **Stig** » Wed Jul 04, 2007 8:51 am

So has anyone blown up an alternator by welding the car's body? I've done a fair bit of welding and never disconnected the alternator first and it's fine. Surely if the welder's earthed close to where the hot bit's going there can't be much current elsewhere, why would it flow all the way up to the engine?
Just wondering if this is an old wive's tale or if there's genuine evidence.

Post by **paulhumphries** » Wed Jul 04, 2007 9:10 am

Stig28 wrote:So has anyone blown up an alternator by welding the car's body? I've done a fair bit of welding and never disconnected the alternator first and it's fine. Surely if the welder's earthed close to where the hot bit's going there can't be much current elsewhere, why would it flow all the way up to the engine?
Just wondering if this is an old wive's tale or if there's genuine evidence.

I don't know for fact but seem to think early alternators had components that could be affected and that is where the advice to disconnect originated.
Although modern items are far more reliable I still disconnect myself as "better safe than sorry"

Paul Humphries

Post by **paulhumphries** » Wed Jul 04, 2007 9:20 am

Probably OTT for what you need but a friend pointed this out to me the other day -
http://www.vehicle-wiring-products.co.u ... o/BDB1.jpg
from -
http://www.vehicle-wiring-products.co.u ... /home.html
It simply clamps to battery pole like any other connector and then provided various fuses for additonal items.
Me - I'd do as Peetee and fit an additional fuse box.
If you want decent battery clamps that allow easy attachement of extra cables then again for VWP -
http://www.vehicle-wiring-products.co.u ... /bt461.jpg
I have these on a leisure battery and can recommend.

Paul Humphries

Post by **chickenjohn** » Wed Jul 04, 2007 9:24 am

A chap on the college course did exactly this on his MGB, (rubber bumper model), welded without disconnecting the alternator/ battery. and the alternator would not charge after that.

Its a good practise and quick and easy to do, to disconnect the battery when carrying out major work on the car- whatever that work entails, especially if a lot of dismantling is involved.

Post by **paulhumphries** » Wed Jul 04, 2007 9:35 am

chickenjohn wrote:
Its a good practise and quick and easy to do, to disconnect the battery when carrying out major work on the car- whatever that work entails, especially if a lot of dismantling is involved.

A battery disconnect is always useful even as a security device.
I've used these on my cars in the past and they work OK -
http://www.vehicle-wiring-products.co.u ... /02100.jpg
In fact it saved one car, a Reliant Kitten.
Someone had used the speedo clamp fixing as an earth. The eye connector was huge and vibrated around until it touched the live on the voltage regulator thus causing a total short and small fire. The fire then burnt though the ignition switch wiring so that turning key off made no difference. Luckilly I had one of the disconnects attached to battery and that stopped short / further damage.
Many hours with soldering iron and mountains of wire the car was repaired but if I couldn't have disconnected battery I suspect there wouldn't have been much to repair !

Paul Humphries.

Post by **Kevin** » Wed Jul 04, 2007 4:08 pm

In fact it saved one car, a Reliant Kitten.

Each to their own I suppose.............

Post by **jtd.75** » Wed Jul 04, 2007 5:17 pm

Hi Johnpaul, I have those clamps fitted on 2 morris's, 1 peugoet 405 diesel estate and had one fitted to a 1967 LD ambulance but only has a means of quick release to isolate the battery. I would follow the advise of our knowlegable forum friends as to fitting any additional electric gismos and make them fuseable.

Post by **8009STEVE** » Thu Jul 05, 2007 9:29 pm

So has anyone blown up an alternator by welding the car's body

Yes I did. It cost me £45.00 for a new alternator. The old one was only 2 years old.

Post by **Stig** » Fri Jul 06, 2007 9:52 am

Fairynuff, I'll unplug it next time!

Post by **chickenjohn** » Fri Jul 06, 2007 11:49 am

BTW, I really like Peetee's solution- an extra fusebox neatly wired in. Where did you get the bits from? Looks almost original type fitting.