Alternator Upgrade

[eugeneb2015]

Hi

It looks like my old 11ac is on its way out, its been noisy for a while and I think the brushes are now too low as I get a flickering IGN light. I have replaced the 3AW, 4TR and relay some months ago...

I have managed to get a new 65amp alternator that is supposed to be direct replacement. 

After trawling the posts on here and other sites I think my only concern is around the cable sizes for the battery connection etc.

From what I understand I need to run new cables from the alternator to the shunt under the steering column and then back to the starter?

The plug on the alternator is a 3 pin type 2 large and 1 small spade terminal. The large terminals are 9.5mm  and will take upto 6mm2 which is 50A, so I need to run 2 cables?





I think the terminals on shunt are 1/2"? so I found a connector on the autosparks.co.uk site that I think make work...




Have I missed anything!



cheers

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[djm16]

My copy of the circuit diagram for a P5B shows the main connection form the alternator goes direct to the ammeter (opposite side from battery).

6mm^2 of good quality new copper cable will easily carry 60A. The alternator will burn out before it does. If you are drawing more than 60A at any time then either you have a problem that needs fixing or you are hearing impaired and running a 500W Woofer.

[eugeneb]

Not planning on a big sub woofer 😜

So would you suggest only 1 6mm2 cable is enough?

I have upgraded the headlights to halogen and added an electric cooling fan. Its easier to get a larger alternator over here in NZ.

[eugeneb2015]

Hi 

So after finally getting round to fitting the alternator I found that the new one I had purchased was too big, even though the mounts we're correct, so back to the drawing board! I managed to find a recon second hand A127 55amp from a Ford Sierra, but apart from the blue accents and ford label, fits perfect. 

To test everything I used the original wiring, is this big enough for 55amps or should I upgrade that as well?

Cheers

Eugene

[enigmas]

Hi Eugene...unless you've got a getto blaster in the car with massive "doof doof" speakers in the boot, the heaviest continuous drain on the electrics will be the headlights...depending upon the wattage (halogens.) To counter this fit a modern set of LED headlights. They're literally plug 'n'play and draw a fraction of the current. 55 amps is fine. I run quite a lot of modern electrical accessories and the 45 amp alternator in my coupe manages fine.

As for the wiring just beef up the alternator main feed wire if it bothers you. It really depends upon the load and draw you place on the eletrical system. Head light/ driving light relays are a good move if you stay with the halogens(?) as the OEM headlight switches can cook under the load. Typical of cars of the period.

[eugeneb2015]

I have an electric fan and halogens and was going to fit relays to protect the switch, I have looked at leds but wasn't sure if they would fit inside the housing. i'll have a read of the thread on here.
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Cheers