Ignition coil wiring

[spider2081]

This is the diagram from Fiat's "Spider 2000 Electrical Diagnostic Manual 1980-81"



I think the Yellow wire in the black sleeve is the wire to the Tachometer. One could check this by disconnecting that wire and see if the car runs but tach does not indicate.
I have found other wire colors that did not agree, wire diagram with my car.

The coil can be rotated in its mount so the coil has to be wired by the physical markings on the coil.

Also the ring terminals from the control unit ( red wire and black wire) usually go on the coil posts first then the tabs for the spades.

Hope this helps

[sierraspider]

Ok-So there's some mixed thoughts on the mysterious yellow wire- again mine's a coax (odd) I want to hook it back up and get it to run but I don't want to destroy another part. So any ideas. Just hook up copper and cut back outer aluminum?

Thanks

[RoyBatty]

the outer metal sheath is for shielding against RF noise.
DO NOT connect that sheath to any kind of power.
Use a multimeter to check for continuity between that wires conductor and the metal shielding. There should be none.

[sierraspider]

So Roy, you're saying I should hook up copper (inner wire) and isolate aluminum (outer wire) from any current.

[RoyBatty]

Yes.
Your description sounds to me like you're dealing with a shielded wire.
If the shielding is connected to anything, or should be to ground, at only one end. Not at both ends.

[sierraspider]

What is being shielded from RF. It's not on any diagrams (Artiques or Fiat shop). I'm going to hook it up . I'm not sure what the chances for a major screw up are .

[spider2081]

sierraspider Can you post a photo of what you have for coil wires and a photo of the wire in question? If the shielded wire you are talking about is something added by a previous owner I would be guessing its purpose.
As Roy stated only the center conductor would be connected. The outer is usually protection for electrical noise.
If this wire is an original Fiat wire I would guess it is the pick up for the tachometer. The reason for that wire being shielded is it physically runs close to the coil and distributor high voltage wires. These spark plug high voltage wires could cause impulses in the wire and make the tachometer inaccurate.

[sierraspider]

Azruss/Roy Batty and all-

Thanks for the time you took to inform me about the "yellow" coil wire. Finally had the time to install it with aluminum strands shielded from copper (with shrink tube). Worked, now on to the next project.


Thanks again

Dan

[Sydmn]

Where are all the pictures responders are refering to?