Ignition switch wiring diagram

[Wfolland]

Have a 1970 Fiat 124BS1 (Euro Model) with all wiring going to ignition switch disconnected, switch is an OE Sipea. Cannot find anything online that represents the exact configuration of the terminals on my switch. The switch has spade connectors ,are not soldered like newer models. Your help please.

[vandor]

Hi, back then there was not that much difference between the Euro and US models, so the diagram's on Brad's page should work:

http://www.artigue.com

[Wfolland]

Checked out Brad's diagrams but they do not indicate a pair (connected together) of terminals marked #16. The P/N of my switch is 90030. Any idea if anyone has a procedure for performing a continuity check on this switch?

[aj81spider]

I'm not sure if your switch is the same as mine (74, US), but the #16 terminal makes it seem that it might be as my 81 did not have that terminal. Here's the pin out of my switch:

Pin 30: Input, brown wire. Feeds several outputs:
Pin 50: connected to red wire to starter, only connected to Pin 30 in start position
Pin INT: connected to light blue/red and dark blue wires, connected to 30 in start and run positions
Pin 16: connected to green/black wire to fuel pump, connected to 30 in start and run positions

Pin 30/1: Input, black wire. Feeds one output
Pin 15: connected to pink and light blue/black wires, connected to 30/1 in start and run positions

To check this you can use a multi-meter. Put it in the "Ohms" position to measure resistance. With the switch in the off position pins 30 and 30/1 should be isolated from everything else (i.e. the resistance should measure "open"). There may be more than one input pin available so if you measure very low resistance between 30 or 30/1 and some other pin that pin is an alternate input for that circuit.

Then put the switch in the run position. You should find that each of the outputs (except 50) measures a very low resistance (essentially the resistance of your probe wires, less than 1 ohm) to one of the inputs. 50 should only measure low resistance in the start position.

This will let you map your inputs and outputs on the switch.

[Wfolland]

AJ,thanks so much for this info and BTW Merry XMass, will check this out as soon as santa does his duty. Do you think the switch as I have described it is not original to my 1970 124 BS1 ?

[azruss]

If you have an 70 switch, there will be no fuel pump connection as the 1438 has a mechanical fuel pump. Many of the later models have 2 "extra" white wires that don't really have a terminal and is used for buzzers, like safety belt, door not closed, shoes not laced or some other nonsense the government has deemed required to save us from ourselves. Other's may confirm, but as i recall. the harness plugged directly on to spade terminals on the back of the 70, where later models were soldered with a pigtail.

[Wfolland]

AJ,
With the engine shut-off should both brown wire (going to pin 30) and Black wire (going to pin 30-1) be hot? this is with switch disconnected from wire harness.

[azruss]

Yes, both black and brown are +12v sources.

[Wfolland]

AJ,
Does the Black wire get it's 12v power once the alternator is turning or does it get power off the battery? are both wires hot without the engine turning over?

[azruss]

On an 80, they both get power from the battery.

[aj81spider]

Azruss 80 seems to be wired the same as my 74. Both the black and brown wires should be hot all the time. According to the wiring diagram I have the black wire comes from a stud on the alternator that also has a wire from the battery landing on it. The brown wire comes from the starter which also has a wire going to the battery. As a result both are effectively connected to the battery and live all the time.

When the alternator starts spinning it will then power everything and the wires to the battery are used to charge the battery.

Merry Christmas to you as well!

PM me if you don't have a wiring diagram and I'll send you what I have. I'm not sure it covers the Euro models, but will be close enough to point you in the right direction.

[Wfolland]

AJ
With your help I think I am on my way to understanding/troubleshooting my ignition switch, will let you know how I make out, thanks again.

[Wfolland]

Ignition switch is rewired and working perfectly, still do not understand the puncheon of the twin pole connection #16 on the switch. Thanks aj.

[baltobernie]

Sorry; late to the party (any wine left? )

For future reference:

[bradartigue]

Ignition switch is rewired and working perfectly, still do not understand the puncheon of the twin pole connection #16 on the switch. Thanks aj.

I have one of those switches, I have no idea where it came from. I used a meter to determine what was turned on when. For what its worth FIAT may very well have used a run of those from another car...so it may be original for your car but not be an exact match to the wiring of all cars within your model year.