Push Button Switch in Engine Bay...?

[qcetc]

I found a push button switch in the engine bay. Has a big rubber black cap with 2 white and black swirled wires....? Looks like the manual says engine bay lights...? But I can not find any lights anywhere in this area.

I know you guys know what this is already huh...

Thanks
Rick

[mdrburchette]

Do you have a pic of it and where it's located? I thought Fiat did away with the engine compartment lights in 71.

[ventura ace]

When you post a question, it is a good idea to let folks know what the vehicle is. We assume most are Fiat spiders, but there are the 850 spiders and the 124 spiders. The year makes a big difference. Name the modifications if you know of any. You may want to just put this info in your signature, and it will be there automatically each time you post.

The early 124 spiders had engine bay lights with a cut-off switch that contacts the hood. Denise suggests that was stopped after the '70 model. My '70 has the engine bay light switch. It also has a push button switch that puts the engine at fast idle. It activates a solenoid that causes vacuum to pull a diaphram on the carburetor to trigger fast idle. I believe the whole point was to assist the technicians for checking polution control function.

Alvon

[MNspiderman]

Without knowing any information whatsoever about your car. Thinking maybe its fuel injection. This button might be placed on the passenger side fender and is an inertia switch that shuts the fuel supply off while in the middle of your front end collision so fuel doesn't fly all over and make things worse.

[kmead]

Presuming this is an early carb car, this switch is for enabling one of the electrovalves in the emission system I believe this is for the fast idle vacuum device. It holds the primary throttle plate open on overrun to minimize NOx emissions. The valve works in unison with the 3rd, 4th 5th switch on the transmission. If you have the Haynes manual its function is detailed on page 63.

Sorry didn't read all the responses above, Alvon already answered this.

[qcetc]

Sorry for not stating what year and all...

It is a 1976 Fiat Spider. The push button is pretty large, about the size of your thumb. Its not a click type button, it just pushes down and release and back up. Does not seem to do anything. I can not find any lights in the bay area. And the switch is just laying there in the mess of other wires...? The wires are white with black striping... The top of the switch unscrews like it could be mounted or something....
And by the way, I was looking for a replacement lighter at autozone and found and exact replacement with the light ring and all for $8.00! The only difference is the chrome one the push in part. Not black like stock so I guess its not exact but darn close.

Thanks
Rick

[baltobernie]

It's right up next to the edge of the engine compartment? Across from the carburetor? Alvon is correct; that is a test switch for fast-idle engagement, emissions-related. If you are subject to inspection, that switch must exist. It doesn't have to actually do anything, however.

Congrats on the cigarette lighter assembly. The universal replacements are the way to go, as they will accept all modern male plugs, something the OEM versions don't do (they're deeper).

[mdrburchette]

The button with wires coming from under it right next to the brake reservoirs is the fast idle emission test switch thing-a-majig... also referred to as an "electric press switch" used to aid in adjusting the fast idle adjustment on your carb.