Wiring sizes / capacity?

[bigmalcy]

Hello again sidescreeners

I'll shortly be embarking on the rewiring of our 3A with a new loom. Of course, there are some wiring connections which I will need to fabricate myself, as the loom doesn't include everything (e.g. many of the bridging connections behind the dash, alternator loom, overdrive loom etc etc).

 

I therefore want to order some wire and connectors from Vehicle Wiring Products to allow me to fabricate these bits and pieces.

 

Can someone please tell me where I can find out what rating of wire I should use for the different circuits in the car? Are there any simple rules of thumb which can be employed to avoid having too many different sizes of wire flying about?

 

Thanks heaps

Malcolm

PS particularly interested in overdrive wiring, alternator harness and dashboard wiring.

Edited February 4, 2013 by bigmalcy

[angelfj]

Hello again sidescreeners

I'll shortly be embarking on the rewiring of our 3A with a new loom. Of course, there are some wiring connections which I will need to fabricate myself, as the loom doesn't include everything (e.g. many of the bridging connections behind the dash, alternator loom, overdrive loom etc etc).

 

I therefore want to order some wire and connectors from Vehicle Wiring Products to allow me to fabricate these bits and pieces.

 

Can someone please tell me where I can find out what rating of wire I should use for the different circuits in the car? Are there any simple rules of thumb which can be employed to avoid having too many different sizes of wire flying about?

 

Thanks heaps

Malcolm

PS particularly interested in overdrive wiring, alternator harness and dashboard wiring.

 

 

Malcolm: Here are a couple of sites that should provide what you need.

 

http://www.triumphrescue.com/BritishWiring_oldsite/CAT02_07.PDF

 

http://www.vtr.org/maintain/wiring-harnesses.shtml

 

Cheers, Frank

[bob-menhennett]

Malcolm

The Vehicle Wiring Products website gives the cable sizes and the capacity of the relevant wiring ( click on the standard cable section ).It also gives the calculation to work out the load.

Have you discounted completely... getting the wiring loom manufacturer to include all the upgrades you want to incorporate ?

 

The extra cost of a bespoke loom, which still looks the part, is usually much neater than a standard loom with loads of extra wires dangling everywhere,

is not as great as you would think.

The extra cost of the loom is usually cheaper than buying the extra add on bits separately.

Just make your wish list as comprehensive as you can, eg overdrive, alternator,Hazard lights, electric fan, 12v socket for phone charger/Sat Nav,rear fog lights,spot lights, extra relays, extra fuses, etc.

Bob

[bigmalcy]

Thanks very much fellas - very useful info.

Bob - while I can see the argument behind getting it all included in a bespoke loom, that would require a fair amount of planning and decision making on various pieces of the puzzle. I quite like the flexibility that using the off the shelf loom will give me, so I'll stick with that, I think... and I'll try to keep it neat

 

Based on what i read in the first of Frank's links, I'm thinking that, for the sake of simplicity, I might adopt the approach of using 17.5 amp wiring for everything except the alternator loom, for which I'd use the 35 amp stuff. This might be a bit inefficient, but it keeps things simple and I can't think of a technical reason not to do it this way.

 

Thanks again

Malcolm

[AlanT]

VWP's thinest wire is OK everywhere except the Ammeter etc as you are planning.

I only found two sizes in use on my 4A loom when I dismantled it.

 

I'm with you, fixing a wiring loom to suit yourself is a worthwhile job.

 

BUT

 

Only if you are used to such work. Lots of posts on here show electrics puzzles a lot of guys.

 

Al.

[AlanT]

Just read you are worried about the OD solenoid.

 

This can take a high current but ONLY for a few seconds until the internal switch operates and then the "holding current" is only an Amp or so.

 

The thin wire is OK.

 

If this switch ever fails to open then the solenoid will burn out. So you might like to add a wire and to generate some kind of warning of this event. I use a buzzer.

 

Al.

[bigmalcy]

Al

Thanks for the input... when I started the project, I expected the wiring to be one of the more difficult jobs to do, but having done some research and studied wiring diagrams, I'm feeling reasonably confident. That could change once i start putting it together, of course

 

With regards to the o/d solenoid, I was aware of this issue and had wondered the best way of confirming that the actuation lever was suitably adjusted to ensure the actuation coil is switched off as intended when o/d is engaged. I had figured on measuring the current through the solenoid to check this, but i'd be interested in how you wired up your buzzer for this purpose?

 

And now you've got me thinking about buzzers, I wonder if a buzzer linked to the oil pressure switch would be a good idea - what do you think? Plenty of boats have buzzer alarms for low pressure / charge / high temp etc, so why not a TR?

 

And last but not least - you may be able to answer another question which has been lurking at the back of my mind for a while: we are fitting the alternator conversion, and I have rewired the generator control box as per some guidance I found on the web (see below). From what I can see, the revised control box is now simply a means of connecting the alternator cables to the ammeter, lighting switch and ignition warning lamp. My question is therefore - can I get rid of the control box altogether and connect the various cables directly? It wouldn't be concourse, but that's not our aim with this car.

 

Thanks in advance

Malcolm

 

 

[RogerH]

Hi Malcolm,

the control box can go, if that is your wish. The TR5 and early 6 had a neat insulated 4 way connector that would suit your needs for connecting all your Alt wires.

For the Alt wiring make sure you have a beefy enough 'Brown' cable. Most Alt's put out more than 35amps and with a few accessories the car can exceed this.

 

Add up all your services - lights, rad fan radio etc and make sure your happy with the total cuurent going through the wires.

 

For your addition wiring VWP also do the black loom tape that can hide a million sins.

 

Good luck

 

Roger

[Dave Larnder]

Hi Malcolm

I too have the alternator conversion and no control box. I also have a Kenlowe fan and high output headlights like modern cars, but I installed 4 relays in the circuit and an 8 way fuse box, information the courtesy of Lee Hutton at NLG who had written an article in TRaction about it, so I took his advice and all is O.K. with no overloading anywhere, and piece of mind, seeings that I don´t understand electrickery at all.

 

Dave

[Menno van Rij]

Easy: http://advanceautowire.com/

 

Menno

[MilesA]

Hi Malcolm

 

I have just rewired this area of my 3A. All power from the alternator and all auxilliaries including add ons (electric fan, electric fuel pump, windscreen washer, heater, 12v outlet) were originally wired through a single, open fuse block as shown in the photo below (the Control Box and attached cables were defunct and for show only).

 

With advice from a number of Forum members, I set about rewiring. I deployed a 4-way block from Revington for the alternator supply and one new fuse box for the original auxiliaries and another for the add ons as shown in the second photo. The result is not original but neither is quite a lot of my car.

 

Ian Cornish has written 2 very useful articles on wiring alternators. If you PM me with your email address I can send you copies of the articles and some further details of the wiring of this set up if it is of any interest.

 

Miles

 

 

[ianc]

The two articles to which Miles refers may be found in Section J4 of the Technicalities CD (originally published in TR Action 118) and in TR Action 248 (March 2011), respectively.

 

The 4-way connector block 150640 is available once again from Revington TR (and from the usual sources which Revington supplies, such as Moss).

 

Ian Cornish

[bigmalcy]

Brilliant, thanks for the input, fellas. I've found the technical articles on the Technicalities CD which offer some good info. I'll digest it all and come up with a plan of attack...

 

Thanks again for everyone's help!