Trailer Wiring on '03 Disco in U.S.

My LR dealer seems to be unable to properly wire the trailer plug
receptacle on our '03 Discovery HSE. The trailer requires a Backup Light
signal to activate a solenoid that disables its surge brakes. =20

The dealer has tried twice now but the wiring is still not correct so =
I'll
be discussing this with him tomorrow. As wired, the backup signal is =
given
only when the LR's lights are on, i.e. Lights off, engine running, =
reverse
gear selected, NO signal.

The other plug signals are correct including the 12 Volt Power and Rear =
Fog
Light signals but the Backup Light signal is an ongoing problem. Why is
this such a big deal???

Thanks,

LB

On or around Sun, 25 Jul 2004 14:50:07 -0500, <[email protected]>
enlightened us thusly:

>The dealer has tried twice now but the wiring is still not correct so I'll
>be discussing this with him tomorrow. As wired, the backup signal is given
>only when the LR's lights are on, i.e. Lights off, engine running, reverse
>gear selected, NO signal

dunno what type of lighting wiring it has, meself. If it's the normal kind
with a wire going to each lamp, then it shouldn't be hard to isolate the one
for what we call the reversing lamp. Still shouldn't, in fact, if it's a
cunning bus system with switches (relays) at the remote ends (as I believe
some vehicles are now using instead of running a forest of wires all over
the place - dunno if they've done such on the disco) - at some point, there
has to be a 12V supply to the back-up lamp bulb, and I imagine that's the
one you want for your brake disabler.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"The breezy call of incense-breathing Morn, The swallow twittering
from the strawbuilt shed, The cock's shrill clarion, or the echoing
horn, No more shall rouse them from their lowly bed."
Thomas Gray, Elegy Written in a Country Churchyard.

On Sun, 25 Jul 2004 21:18:43 +0100, Austin Shackles
<[email protected]> wrote:

>On or around Sun, 25 Jul 2004 14:50:07 -0500, <[email protected]>
>enlightened us thusly:
>
>>The dealer has tried twice now but the wiring is still not correct so =
I'll
>>be discussing this with him tomorrow. As wired, the backup signal is =
given
>>only when the LR's lights are on, i.e. Lights off, engine running, =
reverse
>>gear selected, NO signal
>
>dunno what type of lighting wiring it has, meself. If it's the normal =
kind
>with a wire going to each lamp, then it shouldn't be hard to isolate the=
one
>for what we call the reversing lamp. Still shouldn't, in fact, if it's =
a
>cunning bus system with switches (relays) at the remote ends (as I =
believe
>some vehicles are now using instead of running a forest of wires all =
over
>the place - dunno if they've done such on the disco) - at some point, =
there
>has to be a 12V supply to the back-up lamp bulb, and I imagine that's =
the
>one you want for your brake disabler.

Thanks for your reply. After checking further I've actually found 2 =
errors
in the trailer wiring:
(1) the Fog Light and Backup Light signals are switched in the LR's =
trailer
socket
(2) the signal that would indicate the Fog Light on is present whenever =
the
headlights are on.

I can switch the signals to compensate and since I am not presently using
the Fog Light signal, that's not a problem. (Though I was thinking about
using the Fog Light signal for flood lights at the rear of the trailer.
This would be handy for boat retrieval.)=20

Thanks again,

LB