Fog Light Switch

[Martyn]

I have a European 1985 Pininifarina. It has a rear fog light and switch on dash. I was preparing it for its ITV (road safety test here in Spain) and the fog light didnt work. It turned out the problem was the switch. It appears difficult to buy a replacement.

Any ideas?

PS: Fortunately they didnt test it and it passed.

[spider2081]

can you post a photo of the switch?

[Martyn]

I hope this link works:

https://drive.google.com/file/d/1WTHTkh ... sp=sharing

[18Fiatsandcounting]

Thanks for the picture. Have you thought about disassembling the switch and seeing if it can be fixed? At least on the earlier cars, many switches snap together, so they can be carefully taken apart and cleaned. I've had to do this many times on the switches for lights, hazard, heater fan, courtesy light, etc.

-Bryan

[Martyn]

Thanks Bryan. I'll have a go - nothing to lose.

[davidbruce]

Bryan is right. Often you can disassemble them and it may just need sanding and cleaning of the contacts. A word of warning. There is probably tiny springs and ball bearings in there. If they escape they usually seek the darkest most obscure recesses of the shop to come to rest.

[Martyn]

Thanks David. Good advice.

[Martyn]

I've removed the switch, but not sure how to open it. Concerned about using too much force.

I attach a photo and highlighted a lug, which could be how to open it up. There is similar lug on the reverse.

https://drive.google.com/file/d/1PiDW2E ... sp=sharing

Is this how it is held together? How best to open it?

[18Fiatsandcounting]

These switches are usually designed to be snapped together, but disassembly is not as easy. You're right in that the wrong motions can break a plastic "feature" that holds it together, and then you're stuck. A sticky wicket as you say.

Do you have some jeweler's screwdrivers or something similar? My guess is that by pushing on the tab that you pointed out, perhaps with some coaxing of the square ring that it rests on, the two pieces will pop apart. The challenge is that most likely you have to do this at the same time on both sides, requiring 4 hands. To get around this, I get one side loose and then put something in there to keep it loose (like a toothpick) and then work on the other side.

-Bryan

[Martyn]

I managed to "fix" the switch. So thanks to all.

By the use of small screwdrivers and thin metal pieces to keep things open, it came apart. I cleaned all contacts, put it back together and tested the contacts. It worked as a switch. Or at least when not connected to the car!!!!!!

I now have two problems.

1. The rear fog light is now on all the time when the headlights are on irrespective of the position of the switch. But only if the fog light is not attached to the bracket at the rear of the car. So the switch is seemingly redundant. Interestingly the light to the right of the foglight switch doesnt work. It could be the bulb I guess.

2. When the fog light is attached to the bracket the light doesnt come on but the headlights are much dimmer. I have checked and there is voltage between the securing bolts of the lamp and the bracket. So there is some sort of short circuit?

So any pointers on how best to resolve these issues would be great as usual?

[Martyn]

Hi, I've resolved problems 1 and 2.

Problem I now have is wiring behind switch. Switch is working as it should but wiring going into it cannot be right as fog light is always on when headlights are on. In effect the switch is redundant. Some further investigation required.

Anyway thanks again for support repairing switch.

[scrapironchef]

Head over to to Mirarfiori and check the library for a schematic, get yourself a multimeter and start tracing wires.

[spider2081]

I have a European 1985 Pininifarina. It has a rear fog light and switch on dash.

Is the European version of 1985 Spider different than the US version? I looked on the wire diagrams I have for the 84 and did not see a rear fog light circuit. I looked at a friends 85 Spider and it did not have the rear fog light or switch. Was it an option? Also the 85 owners Manual did not list a fuse for the rear fog light circuit.

I'm curious if Martyn has a Spider that a complete wire diagram does not exist for.

[Martyn]

Hi Spider2081,

Sorry only noticed this today.

The fog light was standard in the European version. The link below shows a picture from the original car manual. To the right of the switch is a light to show that the fog light is on. It shares Fuse E.


https://drive.google.com/file/d/1ODKU3w ... sp=sharing

Martyn

[spider2081]

Thanks Martyn
I looked again at the wire diagram for the 84 and it does show a connection on fuse E for " European Provisions" on fuse E.

Fuse E only has power when the ignition switch is on positions and the head light switch is in the Lo beam position.
I don't have any additional documentation but my guess is the power from fuse E would then go to the rear fog light switch so that when the headlight Lo beams are selected the rear fog light could be turned on or off. There would be no power for the rear fog light switch if the lo beam headlights were not turned on.

This would not be a very intuitive operation for the switch. I would have expected the rear fog lights to have been fused of a "hot all the time " fuse so if the car was parked with the engine off in a foggy situation one could light just the rear fog lights.

So I think your statement

Switch is working as it should but wiring going into it cannot be right as fog light is always on when headlights are on. In effect the switch is redundant. Some further investigation required.

is correct or the switch itself is not operating correctly.