Dash clusters with aftermarket ECU

[appletree]

can any one tell me if i make an adaptor plug using a spare ecu to get a matching plug and then wire the New ECU in to the plug will the dash clusters still work? ie the speedo, rev counter and engine temp?

as far as i can see the loom goes to the cluster and then drops down to the ecu. is this the case???

if not, how do i go about wiring in the clusters to the new ecu loom.

if it makes any difference i will be using an emerald ECU

[Brianmoooore]

Short answer is no.
The only signals that the ECU supplies to the instrument cluster are the engine speed (revs) signal, and fuel rate signal. These signals are used by the rev counter and economy gauge and SI lights, and go on to the OBC if you have one.
Speedo and fuel gauge have nothing to do with the engine or engine loom at all, and the temp gauge only requires a single wire to a suitable sender on the engine.
The rev counter only requires a cleaned up pulse signal, which is probably obtained fairly easily from your emerald.

[Andy335Touring]

For your rev counter you need to conect the signal wire from your Emerald to the solid black wire on the back of the clocks, i didn't need to do any thing else to get mine working ok.

[appletree]

cheers andy did that include the speedo working?

[Andy335Touring]

As Brian said, you don't have to touch the speedo wiring with an ECU swap

[Brianmoooore]

Black wire on the back of the clocks (pin 7, blue connector) is the engine speed signal, and, according to Andy, it seems the Emerald produces a suitable signal that needs no processing.
The only signal that is missing is the fuel rate signal, which will only affect the econometer and some OBC functions.

[appletree]

Ahh i see , i think i will be able to live with out the econometer, i'll probably be able to watch the fuel gauge go down anyway!

[jaistanley]

There will probably be a programmable output on the Emarald anyway. Se if you can't find the strategy behind the signal and program the ECU to output the same thing. It'll only be something simple like a pulse every time the injectors are fired or something like that, the ammount of fuel dependant on the length of the pulse or something. Be really nice to keep all of the features eh?

Jai