stu21t

ive got an aftermarket rev counter to wire in, but theres no wire coming out of my ecu/coil/ignition module.

on the wiring diagram for the L8 ecu it shows a green wire coming from the ignition module, going to the coil, then through a filter???? to the rev counter.
does any1 know what this filter is?

ECU Monitor Enthusiast

iTrader: (1)

Connect your rev counter input to the wire that goes to the NEGATIVE
terminal of the ignition coil.
This wire is normally green on ALL Fords Pre 1995.

That lead goes to the ignition module VIA the inline suppressor filter.


The filter is there to reduce the amount of radiated electrical interference
to the radio in the car.

You could remove it (shorting the wires together) and this will NOT affect
the car in any way but if you listen to non FM radio channels, you will get
ticking and whining noises.

stu21t

cheers m8,
as i have no radio not having the suppressor isnt a prob.

stu21t

so green is negative and black is positive on the coil, b4 i connect to the wrong one.

ECU Monitor Enthusiast

iTrader: (1)

Correct, if you get it wrong, you wont damage anything.

Not unless you connect it to the HT leads off course

The coil will be marked with the correct symbols.
(Will be the smaller round pin if connectors are round type)

stu21t

cheers

stu21t

ive just had a look on mine and the green wire is going to the + on the coil, and i checked on my m8s car its the same?????

so do i connect to the - or the green wire

ECU Monitor Enthusiast

iTrader: (1)

It must connect to the negative side of the coil no matter what colour
the wire is.

I presume your car is a sierra cosworth ?

stu21t

its a kit car with a sierra engine
but my m8s car was a sierra 4wd

they both have green wires going to the + on the coil and black to -

on the wiring diagram ive got for the L8 ecu it shows i connect to the green wire????

ECU Monitor Enthusiast

iTrader: (1)

Try the negative terminal first, if it doesnt work, try the positive.

You wont damage the car or the rev counter if you get it wrong.


If the coil has been wired up backwards, it will still work with only a slightly
reduced spark energy output that may be ok for your state of tune.

stu21t

mine and his are stage 3 ish,
are they meant to be green to - then?

Anonymous

Check with a volt meter if the positive side of the coil is acutally postive or not mate!

ECU Monitor Enthusiast

iTrader: (1)

You will need to disconnect the other side of the coil to check that
properly as the ignition amp will not be switching when the engine is off
and as the coil is low resistance, voltage will just pass through which will
put 12 volts on the other side.

stu21t

so disconnect the wire from the negative post, then measure whats happening at the positive post with the green wire connected?
and ignition on?

strange both cars are the same, is it a common mistake?

stu21t

http://www.siipicossu.com/manuaaleja...20cosworth.tif

this is the diagram which shows the wire from tfi module (ignition amp) to coil is green and goes to the rev counter,

if the rev counter is definately meant to be taken from the negative of the coil then mine and my m8s cars are back to front on the coil. lol

Anonymous

Sounds that way mate!

I guess it happens when people go to a "group a coil" and have to change the plugs they just naturally assume that "black = earth" perhaps?

stu21t

i would assume black means - and green is positive to.

i will give it a try when i get the car back.

Ryan

black is 12v ignition live.

green is negative side of the coil and connects to pin 1 on the ignition amp and goes back to the rev counter.

stu21t

thanks for that.

easier than testing. lol