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Wiring Questions
coozer - 11/3/08 at 10:07 PM

Hi, tidying up the engine bay and I need a lead from the alternator to the positive starter cable.

1. How do I work out the size of battery terminal? Quoted sizes are for square cm area of the cable. Whats that about? I have a 6mm cable.

2. Do the live terminals in the engine bay need to be covered for SVA??

3. is it OK to have the live feed to the alternator fused? There was one spare lead in the fusebox that is fused. I understand its just to start, 'excite' the alternator. Will it be OK?

Blog updated tonight... getting there now
Steve


nib1980 - 11/3/08 at 10:46 PM

quote:
Originally posted by coozer
Hi, tidying up the engine bay and I need a lead from the alternator to the positive starter cable.

1. How do I work out the size of battery terminal? Quoted sizes are for square cm area of the cable. Whats that about? I have a 6mm cable.

2. Do the live terminals in the engine bay need to be covered for SVA??

3. is it OK to have the live feed to the alternator fused? There was one spare lead in the fusebox that is fused. I understand its just to start, 'excite' the alternator. Will it be OK?

Blog updated tonight... getting there now
Steve


Hello,

1) square cm is the cross sectional area of the metal element of the wire. unsure what you need for your application

2) both live and negative should be covered for SVA

3) No idea sorry

hope some of that helps

Many thanks


caber - 11/3/08 at 11:38 PM

1 most battery terminals are a standard size and should be happy with 6mm2 cable

2Live terminal and neg terminal should be covered at the battery. Depending on SVA tester he may want terminals connected to battery positive covered, that would be the starter motor feed and any connections to a battery isolator switch.

3 Feeds to alternator should not be fused.The heavy cable should go to the battery positive I connected mine to the switched side of the battery isolator switch. The small cable should go direct to the ignition light. This is important to get right otherwise the battery will not charge and you will possibly kill the alternator diodes.

best of luck with it

Caber


02GF74 - 12/3/08 at 08:04 AM

quote:
Originally posted by coozer

1. How do I work out the size of battery terminal? Quoted sizes are for square cm area of the cable. Whats that about? I have a 6mm cable.
Are you asking size of cable? The terminal is sized so it fits the cable
The cable from alternator has to have current carrying capacity that exceeds the alternator output - you'll probably have 60A alternator so you are looking a 8.5 mm2; you can use two parallel runs of 6 mm2; Lucas alternator have two spades that are connected together. In practise you'll probably get away with smaller sized cable.


2. Do the live terminals in the engine bay need to be covered for SVA??
Yes. you can buy rubber covers for the battery terminals and use split convoluted stuff with tie wrap other anything else.

3. is it OK to have the live feed to the alternator fused? There was one spare lead in the fusebox that is fused. I understand its just to start, 'excite' the alternator. Will it be OK?
Never seen that done. There already is a fuse in the form of a low power bulb so I would say don't bother.





vindicator - 12/3/08 at 10:51 AM

Hi,

For the battery terminals to be covered, I got a plastic milk bottle(2 lt jobbie) and cut one of the sides so that it covered the whole of the terminal and this went thru SVA ok. It was kept in place by the battery clamp at the front of the battery.

As for the fuse from batery to alternator, I did this and ended up with several problems. It started out as someone suggesting that I fuse everything from the battery. That I did and also included the batery to alternater cable. The problem is that the alternator will supply as much power to the battery as it wants. So using a 15 amp fuse did not last long and blowing it very quickly. Even changing to a 30 amp fuse just started to melt the plastic surrounding the fuse. In the end I reconnected the battery / alternator cable and soldered it back together and covered it in heat shrink.

Now I don't have any problems with charging or the battery going flat while driving.

HTH

www.timr.space.live.com


:{THC}:YosamiteSam - 19/3/08 at 05:06 PM

quote:




2. Do the live terminals in the engine bay need to be covered for SVA??



Steve


the battery terminals should be covered especially - (think the bigger the cable the bigger the current runnin thro it) theory being if your gonna have a crash the metal will bend on impact fuel maybe spilt - a spark - from bare wire on metal... thick covering on those wires is best.. also for msa rules - red for positive yellow for negative.. helps when on track - from me marshallin days as incident / fire marshal - if the car is to be made safe they will cut the wires if they can see them clearly..