Split charge with a Td5

I fitted my first split charge system to an Austin 1800, back in about
1969, when I replaced the dynamo with a Lucas 11ac alternator. It
used a Lucas 4BD twin diode unit.

I've now got a 2002MY Defender 130 and have bought an electronic low
volt drop split charge unit, but when I came to fit it found a problem
with the Td5 standard wiring.

I expected a medium thickness brown wire from the alternator direct to
the battery, which I was going to cut and insert the split charge
unit. But the brown wire does not go directly from alternator to
battery. It goes to the battery via the ECU wiring mass under the rhs
seat, so putting what is effectively a diode in the battery wire will
isolate the ECU wiring!

Anyone any experience of the actual wiring details?

Web Rover says that all Td5 engines in are equipped with a combined
120 amp alternator and vacuum pump, but without removing much of the
plastic cover trim it's difficult to see the wiring to the alternator.

I had also hoped to buy a special controller to increase the control
voltage level to fully charge auxiliary batteries.

Any help would be welcome.

Reg.

"Reg" <[email protected]> schreef in bericht
news:[email protected]...
> I fitted my first split charge system to an Austin 1800, back in about
> 1969, when I replaced the dynamo with a Lucas 11ac alternator. It
> used a Lucas 4BD twin diode unit.
>
> I've now got a 2002MY Defender 130 and have bought an electronic low
> volt drop split charge unit, but when I came to fit it found a problem
> with the Td5 standard wiring.
>
> I expected a medium thickness brown wire from the alternator direct to
> the battery, which I was going to cut and insert the split charge
> unit. But the brown wire does not go directly from alternator to
> battery. It goes to the battery via the ECU wiring mass under the rhs
> seat, so putting what is effectively a diode in the battery wire will
> isolate the ECU wiring!
>
> Anyone any experience of the actual wiring details?
>
> Web Rover says that all Td5 engines in are equipped with a combined
> 120 amp alternator and vacuum pump, but without removing much of the
> plastic cover trim it's difficult to see the wiring to the alternator.
>
> I had also hoped to buy a special controller to increase the control
> voltage level to fully charge auxiliary batteries.
>
> Any help would be welcome.
>
> Reg.
>

Hello,

The wiring from the alternator, goes to the starter, and then with a big
cable to the battery. If you want to isolate the alternator, yoe have to
rewire it with a seperate wire to the battery. My solution for charging a
second battery: http://members1.chello.nl/~t.bloem/defender/power/power.html

greetings,
Tjalf

>Subject: Split charge with a Td5
>From: "Reg" [email protected]
>Date: 22/09/2004 23:20 GMT

<snip>I've now got a 2002MY Defender 130 and have bought an electronic low
>volt drop split charge unit, but when I came to fit it found a problem
>with the Td5 standard wiring.<snip>

There's currently (no pun ;-) ) a thread on the LROI Forum about this

http://threads.lro.com/cgi-bin/wwwthreads/showflat.pl?Cat=&Board=defender&
Number=488309&page=3&view=collapsed&sb=5



Steve. Suffolk.
remove 'knujon' to e-mail

> > I've now got a 2002MY Defender 130 and have bought an electronic
low
> > volt drop split charge unit, but when I came to fit it found a
problem
> > with the Td5 standard wiring.
> >
> > I expected a medium thickness brown wire from the alternator
direct to
> > the battery, which I was going to cut and insert the split charge
> > unit. But the brown wire does not go directly from alternator to
> > battery. It goes to the battery via the ECU wiring mass under the
rhs
> > seat, so putting what is effectively a diode in the battery wire
will
> > isolate the ECU wiring!
> >
> > Anyone any experience of the actual wiring details?

Thanks to Tjalf and Steve. I'll look at the two URLs.

Reg.

Reg,
It's a probably too late for further advice but after years of travelling
the outback and trying all the gismo's for dual battery systems the simple
180amp relay with the latching circuit tied to the ignition switch, and a
manual switch in series as well, works the best. As a bonus there is no
voltage drop from diodes or silly programming from computer chips. I once
had a setup that equalized the batteries after you stopped the vehicle.
Worked fine until one battery went partially short!
Use battery or welding cable (better as it has more strands and is cheaper
generally) to tie the batteries together through the relay.
I run the main battery and two 110amphr deep cycles with this method in a
td5 defender130.
all the best
............peter.


Reg wrote:

> I fitted my first split charge system to an Austin 1800, back in about
> 1969, when I replaced the dynamo with a Lucas 11ac alternator. It
> used a Lucas 4BD twin diode unit.
>
> I've now got a 2002MY Defender 130 and have bought an electronic low
> volt drop split charge unit, but when I came to fit it found a problem
> with the Td5 standard wiring.
>
> I expected a medium thickness brown wire from the alternator direct to
> the battery, which I was going to cut and insert the split charge
> unit. But the brown wire does not go directly from alternator to
> battery. It goes to the battery via the ECU wiring mass under the rhs
> seat, so putting what is effectively a diode in the battery wire will
> isolate the ECU wiring!
>
> Anyone any experience of the actual wiring details?
>
> Web Rover says that all Td5 engines in are equipped with a combined
> 120 amp alternator and vacuum pump, but without removing much of the
> plastic cover trim it's difficult to see the wiring to the alternator.
>
> I had also hoped to buy a special controller to increase the control
> voltage level to fully charge auxiliary batteries.
>
> Any help would be welcome.
>
> Reg.