First test drive - the car was so happy to be back on the road it won't turn off

[tdskip]

Happy Friday all, hope it has been a good week.

So my first real road test was a 99% success with a 1% somewhat big deal for daily use. She ran great, new brake and cooling system seems happy and the gearbox shifts crisply. Engine seems happy with decent oil pressure even when hot. Love how she drives even with needing suspension bushings etc - that is all the 99% good stuff.

The 1% fly in the ointment is that when I went to get gas the car wouldn't turn off even when you rotate the key all the way off and removed. While a cool party trick it would be kind of nice to be able to turn the car off without having to pull a battery cable to stall it.

Is this a common thing? How hard is swapping in a new ignition switch?

Thanks!

[ORFORD2004]

If you unplug the battery and the car stall, your alternator is not working.

[tdskip]

Hi - oops, that is right. I just stalled it with the clutch. I get over 13v at the battery when running. So alternator is working.

Thanks for the response.

[18Fiatsandcounting]

Is this a common thing? How hard is swapping in a new ignition switch?

Quite common, actually. The Fiat Spider ignition switch has to handle many 10s of amps of current depending on the electrical circuit, and thus over the years, it's fairly common for the switches to act "goofy". Sometimes the starter just "clicks" when you try to start the engine, and sometimes the engine won't shut off.

It's not too difficult to replace the ignition switch, but opinions vary as to how good the modern replacement switches are as compared to the original Sipea ones. There are also those individuals (me for example) who take apart the switch and try to rebuild it, sometimes with success and sometimes not.

On later model Fiats, there is also a path for electricity to still get to the distributor even when you turn the key off, apparently through the alternator, but I have not heard that this is a problem on early spiders such as your '68.

Anyway, food for thought, and in the meantime, an effective way to kill the engine is to put your foot on the brake and slowly let out the clutch while in gear... Ahhh, the joys of Fiat ownership!!!

-Bryan

[spider2081]

I tried to respond this morning but I think the site went down.
Do you have a sire diagram for the car?
Do you have the original Sepia ignition switch in the car??
Do you have the original alternator in the car??

The early Sepia ignition switches ( first generation seldom if ever fail in the "on" position.
I would check for voltage at the coils B+ terminal when the ignition key is in the off position or removed from the switch.
If voltage is present at the coils B+ terminal when the ignition switch is off I wold remove one wire at a time from the back of the ignition switch. The brown wire and the black wire bring power to the switch. I think on early Spiders the black wire is connected to the blue/black wire to power the coil. Disconnect the brown and the black wire from the ignition switch (one at a time) being sure you know exactly what terminal they belong on. If the power remains on the coils B+ wire when either wire is removed from the ignition switch chances are the ignition switch is not the issue. It could however be connected improperly.
I believe the coil should have a blue/black wire on its B+ terminal. If not is there a blue/black wire disconnected in the area of the coil??

[tdskip]

Thanks for following up, this is very helpful. I will try to dig into this tomorrow and report back.

[tdskip]

Guess what fixed itself over the weekend? Went to fired Up yesterday and the switch repaired itself and works properly now.

Despite the ignition switch fixing itself I wasn’t able to drive the car because the fuel pump stop working, I have a low pressure electric pump that I was going to wire in just to be able to use the car before the rains come but wanted to ask where I should pick up ignition switch to power for that.

Is there anywhere in the engine compartment short of the coil where I could pick up ignition switch power as a temporary workaround?

Thanks and hope everybody had a good weekend !

[18Fiatsandcounting]

Is there anywhere in the engine compartment short of the coil where I could pick up ignition switch power as a temporary workaround?

The electric fan circuit? I think later model spiders had an electric fan that would continue to run for a bit even after the ignition switch was turned off, so fan power wasn't ignition switch-controlled (definitely true for the horn and hazard flashers). However, I seem to recall that the electric fan in my '71 would turn off if it was running and I switched off the ignition.

So maybe the original circuit for the electromagnetic fan clutch in your '68 is controlled by the ignition switch?

-Bryan

[tdskip]

Good morning, thanks for the response.


Let me get a multimeter on that.

[RRoller123]

Fan circuit on the later cars is ALWAYS hot at the thermo-switch at the bottom of the radiator, so the fan comes on whenever it is needed, regardless of the ignition switch or engine status.

[tdskip]

Thanks - getting weak volts there all the time so something else to look into (I have a fan switch elsewhere on my car now).

Looks like I need to run the wiring back into the cockpit, doesn't seem to be much that is ignition switched to connect to in the engine bay (not using coil).

[spider2081]

Is there anywhere in the engine compartment short of the coil where I could pick up ignition switch power as a temporary workaround

What year is the Spider you are working on??
Have you Joined Mirafiori.com to access their library of wire diagrams??

some early year Spiders have a Radiator fan relay mounted in the engine compartment on the driver side fender well. The ignition switch has to be the the "run" position for the radiator fan to have voltage at the fan motor. The switch at the bottom of t he radiator switches t he other side of the fan motor to ground. On those cars the ignition switch has to be in the "on" position and the coolant temperature over 190 degrees for the coolant fan to run.
I believe on those cars Switched and fused power is available at the coil of the coolant fan relay coil.

[tdskip]

Good morning. I have a 1968.

Let me check that once it stops raining and I will check out that site.

Thanks for the response.