Adding fog lights

[Dreamcatcher1]

Anybody know if I can hook up aftermarket Bling Light fogs to the factory switch? Car did not come with fog lights and I want to add them but would like to use the factory head light switch. All the wiring is in the car already but when I hooked up head light switch I only get a reading of .5 volts at the factory fog light plugs. Any ideas?

 

[rooSTer]

Your ST didn't come with foglights or are you talking about a regular Fiesta?

 

[Dreamcatcher1]

I'm adding these to my wife's SE. All the wiring is there but there is not 12 volts at the lights, only like .5 volts. I just don't understand how these new vehicle lights work without 12 volts going to them.

 

[Sekred]

I'm adding these to my wife's SE. All the wiring is there but there is not 12 volts at the lights, only like .5 volts. I just don't understand how these new vehicle lights work without 12 volts going to them.

Typically new cars use electronic control modules for many components. The obvious example is the engine but the instrument panel has its own control module. When the input switches are operated ( for example, the high beam switch ) a signal is sent to the control module and the control model then switches the circuit on. These type of electrical systems are generally refer to as Multiplexing.
Are the fog lights an option on the SE Fiesta?. What you will probably find is that you will have to take the vehicle to a Ford dealer and they will need to connect to the vehicle system with a lap top and the Ford soft ware and have the fog light function switched on if its available.
Confused, its not easy to understand but there are benefits.
I have loaded a YouTube clip explaining Multiplexing, its in reference to Freightliner trucks but the principles of how the system work are the same

[video=youtube_share;ASDPhEw-9XI]http://youtu.be/ASDPhEw-9XI[/video]

 

[Dreamcatcher1]

I get the system but was told by the dealer that the car is already set up for the lights (wires are there) basically just need to change the light switch and the system will work. The factory part for this car is the same as the part for my 2010 Focus so I pulled the lights out of the Focus and tried them. The Focus gets 12 volts at the plug when turned on, the Fiesta gets .5 volts. Even the headlights on the Fiesta only show .5 volts at the plug. According to Ford both cars use the same bulbs and they are 12 Volt. Guess I'll call the dealer again. Thanks

 

[Sekred]

I get the system but was told by the dealer that the car is already set up for the lights (wires are there) basically just need to change the light switch and the system will work. The factory part for this car is the same as the part for my 2010 Focus so I pulled the lights out of the Focus and tried them. The Focus gets 12 volts at the plug when turned on, the Fiesta gets .5 volts. Even the headlights on the Fiesta only show .5 volts at the plug. According to Ford both cars use the same bulbs and they are 12 Volt. Guess I'll call the dealer again. Thanks

Very strange, I'm no auto lec so I'm out of ideas at the moment, but have you try connecting the lights and switch to complete the circuit and seeing if it works. Sounds like the circuit needs to sense load before it will supply voltage.

 

[STooge]

The if the switch doesn't have the fog light switch in it then there is nothing to tell the fog lights to turn on. The headlamp switch would need to have the ability to turn on the fogs, if it does not have that then there is now way for the switch to do that. If the wiring is there then you should only need the switch and the fog lamps. I don't think Ford is quite as complicated yet as other manufactures. Sek is right about all the control modules I just do not think Ford is that far yet, I'm not saying there are not a lot more control modules in this car as there are in my SVT Focus but I just don't think there are as many in it as say, an Audi.

Bottom line, it should work. But you may need a fuse as well, if it did not come with Fogs, they would not waste the money to put a fuse in an un-used circuit.

 

[Sekred]

I had a problem when I fitted my boost gauge. I wanted to connect its illumination light to the instrument lights so the brightness would match the instruments. I knew I was in trouble when I measured the voltage coming out of the OEM dimmer switch and it varied between 0.2 - 1 VDC. I rang a auto electrician and was told is was not doable. I still think it could be done but its more trouble than it worth so I canned the idea and wired it straight to 12 volts.

 

[STooge]

I had a problem when I fitted my boost gauge. I wanted to connect its illumination light to the instrument lights so the brightness would match the instruments. I knew I was in trouble when I measured the voltage coming out of the OEM dimmer switch and it varied between 0.2 - 1 VDC. I rang a auto electrician and was told is was not doable. I still think it could be done but its more trouble than it worth so I canned the idea and wired it straight to 12 volts.

Is the dimmer its own connector or is it all together with the connector for the headlight switch?

You could do its own seperate dimmer? But if it isn't a bother then I wouldn't bother, ya know.

 

[Sekred]

Is the dimmer its own connector or is it all together with the connector for the headlight switch?

You could do its own seperate dimmer? But if it isn't a bother then I wouldn't bother, ya know.

The dimmer switch is housed in a module with the headlight switch and the headlight beam angle adjustment.

 

[STooge]

I do not believe we have angle adjustment haha... Or I am illinformed. So it is all one then. Like you said though, if it isn't a bother, it would be more trouble than it is wort i think, at this point.

 

[Dreamcatcher1]

Turns out that there is a relay that needs to be in place and then the computer has to be reconfigured to know that the fog lights are there. this car has all the same equipment as the ST's and as the Focus, in fact the parts for the fog lights are the same as the ones the Focus uses. Sounds like it's not that big of a problem just need to take it to the dealer to reconfigure the computer. Thanks for all the input.

 

[Sekred]

Good to know you got it sorted out and the reasons why. Useful information for future reference.