79 308 GTB ignition schematic

Can anyone email me wiring schematic cheers.
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Full car wiring diagrams are instantly and inexpensively available at http://www.FerrariWiring.com or are you after something more specific?

 

I have just fitted new sup/formance ign mudules (single dizzy 2 coil) and and now my Tacho has stopped working need wiring info for the tacho or wat the cause could possible be Cheers

 

Go here:

http://www.ferraridatabase.com/The_Downloads/Manuals_Owners.htm

download the OM called:

Owners Manual 308 GTBGTS 1978

Page 111 shows the wiring diagram for your euro with the single dist & electronic ignition ECUs. Do you still have the MN (brown/black) tach wire connected to the "-" terminal of one of the coils?

 

Have not removed any wires from the coils, the modules plug in behind the coils. I only undid the brackets that hold the coils to the ECU's to plug one of the plugs in.

 

Schematics below are from 3 surrounding years but none show a proper plug in which you aluded to...which is why I included the 1980 which for the first time shows connectors on the drawing and a minor departure from earlier circuits. Re wire colors - G=yellow MN=Brown R=Red AN=LtBlue w/Black stripe. The 'Cu2.5' just means copper wire 2.5 gauge

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Cheers paul,
I put new plug leads on the car then it started potting and faarting at around 3000 RPM, put on a tuning machine disconected 1 ign bank at a time since then it has stopped working i have also fitted new ign mudules as they where rooted

 

I left out color MN=Brown w/black stripe and though I should add that is where you should focus as that is the signal which powers the inoperative tachometer.

This boils down to the breaker points which formerly produced the tach signal and are changed with the new setup. Originally there was two sets, each driving a coil, marked A and B at the distributor. Incidently, that cap and rotor look like an ounce of gold to replace.

 

Do you think while the engine is running and disconnecting one bank would fk up my tacho (take it the brown wire, front coil is my feed) car has electronic ign
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No I wouldn't but it might depend on how you disconnected that bank while it was running. The coil and internal distributor condensor suppresses large spikes but drop the coil out at a bad moment and the tach may have become a casualty. Hope not.

Next step since the wiring connections looks ok is to move the brown wire to the rearmost coil. I take it the car runs ok since you've not mentioned anything wrong in that department. While you have that brown wire off, inspect the wire by feel for breaks as far down as you can. The continuity of the wire may have become pinched/broken in the module change process.

 

Found the reason for my tacho not working !! she only running on 4 cylinders, the front bank closest to the rear w/screen is not firing, maybe one of the new impulse units is rooted, how would you check to see if it's sending the signal. Cheers paul

 

I'm really not familiar with the new ignition modules you are using but the front bank module must receive a signal from the distributor points or from a flywheel sensor to fire, no? Without a signal there's no spark and no tachometer.

At this point I don't have enough knowledge about your new whizbank to suggest anything. But think you have enough clues to continue in the proper direction.

 

Swap the two "new" modules -- if the "no spark" problem moves to the other bank (and your tach starts working ), you can be fairly certain that that "new" module is bad. If the "no spark" problem stays on the same bank, then it's either a problem with the pickup inside the distributor for that bank or some sort of wiring problem on that bank.

PS It would've been better if you could have correctly found/described this situation in your original other thread!