Power Supply for Digifant ECU

Hello Everyone,

Hope you're well.

I have a MK1 Caddy that was originally a 1.6 Diesel. We've almost finished an engine conversion to a MK2 GTI 8v, but having problems with the electrical side of things.

Does anyone know where the Power Supply comes from for the ECU? And also the Earth?

Any advice would be greatly appreciated.

Thanks,
Jay

I've already replied to your PM but for the benefit of anyone else who stumbles across this one:

if the ECU loom was unbutchered when you got it the wiring is simple, you either have 2x 2 pin spade plugs or 1x 5 pin junior timer plug which provides all the power and trigger feeds to/from the ecu to the fusebox.

common to both:
red/yellow - fuel relay trigger - D/13
yellow/black - ecu relay power
green/red - starter cranking live - spade on C/18, or tap to main starter red/black

5 pin only:
red/black - fuel injector power - Spade N or ECU relay power
red/white - lambda power - ignore, not used

With the ecu relay power you will either have to wire your own relay above fusebox, or if you have a proper full digifant CE1 engine bay wiring loom it comes from the small 2 pin green plug 'R'

with the injectors on CE1 looms with the spades its looped to the ecu power, on CE2 looms it goes to a large spade connector Z/1, the CE1 equivalent to this is N. Either way its fine.

There are 2 earths on the digi loom, one goes to the side of the head and the other direct to the battery.

Main thing to be sure of is your engine is well earthed. if it isnt, the starter motor will earth itself through your ecu, blowing it up.  Be sure you have late mk2 & mk3 type gearbox earth point, to a stud on the rear-upper engine -> gearbox mounting bolt.  I would also upgrade to mk3 golf batter,y starter and alternator cabling while you're doing this as they are nice and chunky plus have a better battery clamp. with the earth to chassis the mk3 cable wont reach so you'll have to make up your own short cable to reach here. I just get 2x mk3 earth cables and cut the 2nd one down so I have a length with a ring either end, put 1 end to chassis leg and other end attach to the main earth middle ring with a nut and bolt. You'll see what I mean!