I've spent the last couple of days working on the wiring loom and dash.
I fitted the VDO instruments and switches including a Hella hazard switch as it has the requisite 7 connectors, a Lucas 2 way ignition switch and a push button starter. Delta rocker switches are used for head / sidelights and fog lights. I have not sorted the horn or dip / main switches yet.

Is this why people buy a Digidash? I was tempted but I feel the Riot is better suited to the more traditional discrete instruments even though they are an utter pain to wire up.

Next time in the garage I'll be tackling the engine bay including the ECU.

I really struggled yesterday. I could not find a suitable position for the fuse boxes, relays and flasher unit. I finally opted to mount them under the steering column cover. OK, I realize that I'll have to remove 6 bolts to change a fuse, however I'm hoping not to be doing that too often!

To make matters worse, 2 wires came adrift from the fuse boxes. It took me a while to work out how the fuse boxes come apart. I contacted Premier Wiring (new phone number 0131 554 0099) and they sent me some new crimp connectors.

You can also just make out at the top of the picture the 2 pieces of the loom coming through the bulkhead. Again a struggled to find an elegant solution for the cable routing.

I had originally sourced a header tank from a Rover 214, however I wasn't too happy with its size.
Hunting around my local scrapyard, I found this header tank from a VW Golf. It fits very nicely in the space available. I am going to relocate the air filter. You can see the big 70mm elbow just below the header tank.

Below is the filter I'm considering. C7010 is the most compact filter with a 71 mm O/D neck.



I bought a loom from Premier, however the first thing I did was to pull it apart! I've removed the wiper, washer and heater wiring and significantly shortened the dash loom. I'm going to have to add wires for the fuel pump and fan relays, they are controlled by the ECU mounted in the rear.

Cracking the Colour Code!

OK a bit of an excuse! I haven't done any real work on the car over the Christmas period, too much singing!

What I have done is work out the colour coding for the Focus ECU loom. I tried Googling but have been unsuccessful finding the required information. So here goes!

My engine was supplied with the remnants of the Focus engine loom; it had been unceremoniously chopped off at the ECU. I want to use as many of the connectors and cables as possible. I have an Emerald K3 ECU, so I need to connect injectors, coil, idle air valve (IACV), coolant, air temp crank position (CPS), lambda and throttle position sensors (TPS), fuel pump, fan and tacho.

In general Ford looms use black wires for earth and brown for power. However this does not hold true for the engine loom.

Please be aware the the colours below are for a 1.6 Focus loom. Zetec powered Fiesta looms are similar but not the same.

Green / blue cable is an ignition switched live. It powers the injectors, coil, lambda heater and IACV.
Black cables with a trace colour are ECU controlled switched earths. These trigger the coils, injectors and IACV.
Brown wires with a trace colour are sensor grounds. These are for sensors that require an accurate ECU derived ground reference; connecting to the chassis won't do. These include the temperature sensors, TPS, CPS and lambda sensors.
White wires, solid or with a trace colour, carry signals from the temp sensors, TPS, CPS and lambda sensors.

OK so that's the high-level overview, now for the details.

Injectors
black / white cylinder 1 ECU 24
black / orange cylinder 4 ECU 24
black / yellow cylinder 2 ECU 23
black / blue cylinder 3 ECU 23
green / blue ignition +12v connect to power relay

Coil
black / green cylinders 1 and 4 ECU 25
black / orange cylinders 2 and 3 ECU 5 (watch out same as inj 4)
green / blue ignition +12v connect to power relay
(Not sure if the above is correct. I have switched 25 and 5)

Idle Air Control Valve
black / yellow switched earth ECU 3 (watch out same as inj 2)
green / blue ignition +12v connect to power relay

Coolant Temp
white / violet signal ECU 33
brown / white sensor ground ECU 30

Air Temp
signal ECU 16
sensor ground ECU 30
I don't have cable colours for this as the air temp sensor is in the Temperature and Manifold Absolute Pressure Sensor (TMAP) sensor in the Focus. Strangely the TMAP sensor is not mentioned in the Focus Haynes manual. Anyway I plan to use it. The K3 allows the temp sensors to be configured. It seems that Ford have standardised on the calibration of their temp sensors (air and coolant are the same).

0c = 94k ohms
50c = 11k ohms
100c = 2.2K ohms

I have not tried the above yet but will report back along with wire colours.

Throttle Position Sensor
brown / red sensor ground ECU 30
yellow +5v supply ECU 9
white 0 - 5v signal ECU 8

Crank Position Sensor
cable screen ECU 29 - one end only
white / red signal ECU 31
brown / red sensor ground ECU 32
Use shielded twisted pair microphone cable if not using Ford cable.

Lambda (Narrow)
white signal ECU 7
brown sensor earth ECU 18
green / blue relay controled +12v heater supply
black / yellow heater ground - connect to chassis

ECU pin 36 can be used as a switched ground to control the heater relay.
For wideband wiring see K3 manual.

Fan
ECU 6 switched earth

Fuel Pump
ECU 20 switched earth

Tacho
ECU 12 0-12v pulse

I think that's it! Please email me or leave a comment if I have made any errors.
Once I have tested the above, I'll post a page on the Sylva web site.