Locust Wiring
Based on an article at www.locost.learnfree.co.uk
General Points
If
you are using the wiring loom from an existing car you
should be able
to simply plug in the components and switch on. You may have
to modify
your loom because the loom does not fit your chassis i.e too
long, or
you want to fit additional components or you want to remove
the wires
for components you haven't fitted.
Dismantling
When
you take the loom out of your donor car it is really
essential to label
all the connections as you go. You can do this with bits of
white
insulating tape and a permanent pen. Don't rely soley on the
circuit
diagram of your manual as there may be differences.
Renovating and installing a loom
The
old wrapping will be dirty, it could hide all sorts of
badly-done
repairs and breaks. Take the opertunity to take the wrapping
off and
replace it later. Leave on the tapes you will find
underneath at
junction points - otherwise the whole thing will collapse
into a
tangle. You should find once the loom is bare that you can
see what
goes where and how the system fits together, which makes
life so much
easier. Once you start putting the loom into the car, do it
without
re-wrapping it so that you can adjust exit points of wires
from the
loom, put in extra wires (e.g rear fog lights) and remove
ones you
don't need (rear window heater, courtesy lights). Tape the
exit points
where wires come out of the loom. Get all the connections
sorted. Then
with everything connected, test the whole lot. Then you can
re-wrap the
loom, using non-adhesive pvc tape. - you don't need to take
it out of
the car to do this. Don't forget to put grommets onto the
relevant
parts of the loom before you put all the connectors on and
before you
wrap it.
Escort Wiring Loom
There
are colour codes for vehicle wires. In fact there are
several sets of
codes - older British cars have one set, older continental
cars like
the Escort have another (DIN standard), and this seems to
have changed
in more recent cars. The main colours in the Mk1 and 2
Escorts are:
Colour | Main uses | Examples |
Red - | direct supply from the battery, always on. | Starter cable from battery Cable from Alternator to battery and ignition switch Supply to steering column switches for lights Supply to courtesy lights and clock |
Black | switched supply (and negative battery lead) | From Ignition switch position 2 to
components which are only on when ignition is on. The supply wire for the reversing lights is black. |
Black / yellow | ignition circuit | supply to coil, tachometer, instrument voltage regulator |
Black / red | ignition switch start position | to starter solenoid |
(also) brake lights | ||
Black / green | offside indicator | |
Black / white | nearside indicator | |
Black / green / white | supply to indicators | |
Black / blue | supply to washer pump | (can also be supply from ignition switch to solenoid) |
Brown | all earth wires (to chassis) | |
Brown / yellow, Brown / green, Brown / white |
switched earth (I think) | circuits where the switch is on the earth side of the circuit rather than on the supply side - parts of the heater circuit, the brake warning light circuit and bits of the wiper delay. |
Grey | sidelight / panel light supply | divided into - see below |
Grey / yellow | panel lights | |
Grey / white | nearside side lights | |
Grey / red | offside side lights | |
White | headlight main beam | |
Yellow | headlight dipped beam | |
Blue / black | fuel tank to fuel gauge | |
Red / white | temp. sender to temp. gauge | |
Blue / green | oil sender to oil warning light | |
Green | wiper supply | slow speed |
Red | wiper supply | high speed |
Pink / white | ballast resistor wire to coil |
You may have a serviceable battery. If not you can buy one
for about
£40, Don't mess about with second hand units from scapyards.
Headlights
The
Escort loom may be too short to reach the headlight units.
You cantake
a pair of headlamp looms from a Mini: they have a bulb
holder for the
sidelight which then lines up with the gap in the reflector
of the
standard Escort round sealed beam unit, which means you
don't need
separate side lights. The wire colours for this part are:
black =
earth, red = sidelight, blue / red = dip, blue / white =
beam.
Repeater indicators
Some
posh Escorts had these but most did not. hey should be wired
in with
the front indicators, by connecting feed wire to feed wire
and earth to
earth.
Wipers
Assuming you are using a BL wiper motor, you have the
problem that the wire colours are different to those on the
Escort.
The
Escort has five wires to the wiper motor, in two groups -
two power
wires (green and red, from the column stalk) which have a
grey plug,
and three other wires via a black plastic connector to a
headlamp-type
plug on the wiper body (these are the motor earth and the
park wires).
The
BL motor also has five wires doing the same jobs, going to a
5-way
multi connector with 4.8mm female spade terminals which
plugs into the
wiper unit. You should cut off this connector with as much
wire to
spare as possible when you get your motor from the
scrapyard. You can
remove the wires from it by poking a small pointed object
into the
business side of each terminal - there is a small cut-out -
and bending
the non-return lug flat. This allows you to use new
terminals. Or, you
can leave the wires in place and make soldered connections
to the
Escort wires.
The big question is, which Escort
wire to which BL wire? OK - BL black is the motor earth,
which goes to
Escort brown / white. Escort green is low speed, and goes to
BL
red/green. Escort red is high speed, going to BL blue/green.
Escort
black/violet is the park power supply and goes to BL green.
Escort
black/brown is the park earth and goes to BL brown/green.
If
your Escort has a wiper delay (marked on the column stalk,
plus you
have a large red relay like a flasher relay) then this will
work fine
with the BL motor. Its wiring isn't detailed in the Haynes
manuals, so
I can't help if you don't have one but want to add one.
Dashboard switches
There
are many ways to connect the various items that were
controlled from
the stalk switch on the Escort. Most people use individual
dash mounted
switches for the various components but beware of the SVA
requirements
the old type of toggle switch can not be used. You will have
to source
the safer rocker switches.
Hazard switch
Your
hazard lights must work with the ignition off or on. The
original
Escort loom uses only one flasher unit to work indicators
and flasher,
and does this by having a special switch. The switch has
seven
terminals: 1: flasher unit feed (two terminals, a
black/yellow feed
wire and a black wire to the flasher unit) which is "on"
when the
hazard lights are off), 2: battery input (two terminals, a
red and a
brown which gives power to the flasher unit when the
ignition is off)
and 3: hazard flasher supply (three terminals, a
black/white/green
input from the flasher unit and two outputs to the lights,
black/green
and black/white. The switch keeps the battery input and the
hazard
flasher supply groups of terminals separate (otherwise the
hazard
lights would be permanently on). If possible use this
switch.
A
standard after-market hazard switch has only six terminals,
in a group
of two and a group of four. You need a separate flasher unit
for your
hazard lights if you change to one of these switches.
Proceed as
follows: take a battery feed (red) wire to the B terminal of
the new
flasher unit, and put in a new wire from the L terminal to
the new
switch. Connect the two wires which were on the old flasher
unit feed
to the pair of terminals on your new switch. Lose the
black/white/green
wire (cut it off short and tape it back into the loom).
Connect the
remaining three wires (black/green, black/white and the red
supply
wire) to any of the four other terminals (I mean one
terminal per wire,
not all wires to one terminal!). If your new switch has a
telltale
lamp, take a short wire from the fourth terminal to the
positive side
of the lamp, and an earth wire from the negative side to
earth.
Rear Lights
There
are many ways of getting a set of rear lights, such as
buying a trailer
lighting board. For SVA purposes you must have: indicators,
stop lamps,
tail
lights/rear side lights, a rear fog light and two
reflectors.
Electric cooling fan
Assuming
you are putting in a cooling fan and using a x-flow engine,
you should
have got a Fiesta (or similar) temperature switch in the
thermostat
housing you found in the scrapyard. To get this to control
your fan you
could just wire a supply to one side of the switch and the
other to the
fan, taking the earth lead from the fan to the chassis
(after checking
the fan is blowing or sucking as required). However you
ought to use a
relay to switch the fan on and off. You need a simple (and
cheap)
4-blade relay - The relay will have the following numbers on
the
terminals: 30 (supply from ignition switch terminal 30, i.e.
on when
ignition is on), 87 (output to fan), 85 and 86 (switching
current - it
doesn't matter which terminal is wired "live"). Proceed as
follows: run
a cable from the black terminal of the ignition switch or
from the
fusebox to the relay terminal 30. You ought to have an
in-line fuse in
this cable. Connect the output from terminal 87 to the fan
input,
connect the fan output to the chassis. Connect a similar
feed wire
(which could be the same one) to the control input, terminal
85.
Connect terminal 86 to one side of the temperature switch,
and the
other side of the temperature switch to earth. Do not
connect the fan
circuit (heavy current) to terminals 85 and 86, as this
won't work.
Dashboard (adapting to non-Ford instruments)
The dashboard wiring tends to get messy because unless you
have a removable scuttle it is hard to get at. The main bits
are:
Panel
lights and earth: You should have panel light feed wires
(gray/yellow)
hanging out of the dash area of your loom - they often get
cut and
adapted in the life of a car as accessories are added and
removed. They
go to the panel lights, preferably only using one wire to
keep the mess
at bay. Depending on the instruments you are using,
illumination will
differ. With after-market gauges or salvaged Smiths ones,
the panel
lights sometimes have a red feed wire and black earth wire
because of
the old British standard system. If you want dimmable panel
lights all
you need to do is find a dimmer switch in a scrap car and
wire it into
the FEED wire. Don't put it in the earth wire unless you are
sure no
other dash components are using that particular wire.
Voltage
regulator: Screwed to the back of the Escort instrument
cluster is a
small rectangular box, probably a bit rusty. This has two
springy brass
contacts on it. This unit is the instrument voltage
regulator, and
governs the voltage used by electrical gauges (fuel,
temperature etc).
It has an input and an output terminal (input is right-hand
side as you
look at the back of the Escort cluster), and if you connect
it back to
front it won't work. It needs to be fixed somewhere under
the dash, and
you then connect its original black/yellow feed wire to the
input and a
feed wire from the output to the various gauges' input
terminals. You
can use 6.3mm spade connectors on the unit if you snip off
the
bent-back part of the terminals.
Tachometer:
These instruments use the pulsing of the ignition circuit to
show
engine speed. There are 2 types of tacho you may meet. The
older
Escorts had one continuous wire from the coil negative
terminal through
a sensor on the back of the tachometer and back to the
distributor.
Some Smiths tachos use the same system. Happily, later
models are more
sensible: they have feed wire (black/yellow) and a trigger
wire (should
be green), the trigger wire coming from the coil negative
post but not
going back to it.
Telltale lights: When you
took your loom to bits you marked the connectors, of course.
The one or
(for tacho-equipped cars) two instrument connectors are as
follows:
tacho trigger (green), tacho supply (black/yellow), panel
light supply
(grey/yellow) and earth (brown) make up the smaller
connector. The
bigger one has: panel supply and earth (as previously),
indicator
telltales (right is black/green, left is black/white), beam
telltale
(blue/white), fuel sender (blue/black), temp sender
(red/white),
voltage regulator feed (black/yellow), oil pressure sender
(green/blue), charge warning sender (blue). If you want to
use
alternative telltale lights, you need only wire the relevant
sender
wires to one side of your new lights and the other side to
earth. The
exception to this is the oil pressure light, since it earths
through
the engine block. This circuit needs a live feed to its
telltale lamp
(it uses the voltage reg. feed in the original dash) and the
blue/green
wire goes to the negative side of the lamp, thence to the
sensor on the
engine.
Fuse Box
If
possible fit the origional Escort fuse box. Because the
connectors to
the box are moulded onto the loom I would not advise getting
an
after-market fuse box.
Starter and solenoid
If you are staying with the Escort engine and gearbox
simply mout the Escort solenoid some ware suitable.
If
you want to change an inertia starter for a pre-engaged one
(if you are
using a Sierra gearbox), you won't need the old solenoid
because the
pre-engaged starter has the solenoid mounted on it. After
you have
finished modifying your Sierra engine backplate to get it to
fit your
x-flow (the x-flow plate starter holes don't match a sierra
gearbox)
you need to make the connections as follows: red battery
cable - the
big one - to the big terminal on the starter solenoid, and
the
black/red cable which was connected to your old solenoid,
which runs
from the ignition start position, to the small terminal.
There is a
third terminal on the solenoid, but it is the output to the
started
motor and should not be touched.
SVA
There are several sections of the SVA test which affect the
electrical system.
Lights
and position of lights: You must have the obvious lights
(indicators,
hazard lights, headlights, sidelights, stop lights) and also
a rear fog
light. The units must either be E-marked or else give an
light
equivalent to an E-marked unit. There are detailed
instructions for the
position of lights relative to the sides of the vehicle and
to the
ground, and angles of visibility - you really need the SVA
Tester's
manual for this, but you ought to get it anyway.
Security
/ tidiness of wiring: Untidy wiring, poor connections or
lack of
protection for the loom from abrasion or heat could all be
failure
points, as they could for an MOT test.
Compulsory components :
A
brake fluid warning light which is visible to the driver and
which
illuminates when the level in either brake circuit is low.
The light
must be fitted with a test switch to allow you to test the
warning
bulb.
A hazard light circuit with a switch which has a telltale
light visible to the driver.
A
rear fog lamp whose switch has a telltale light visible to
the driver.
The fog lamp must not operate in conjunction with the stop
lights.
Telltale lamps for left and right indicators and for main
beam (visible to the driver).
Stop lights operated from the brake pedal or brake fluid
pressure.
Dashboard projections: When you choose switches, remember they are not allowed to project more than 5mm from the dashboard in most instances, which means you need rocker switches.
Most British cars tended to use the Briish Standard BS-AU7
to
deturmine the colour of wire to each component Lucas used
this. A list
can be found here. Lucas wiring Colours
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