Aftermarket Foglights

I have a 09 Cobalt Lt and I would like to wire up a set of aftermarket foglights so they will come on with my lowbeams. My car didn't come with factory foglights. Can anyone tell me how to do this?

Mount them where you want them to be then wire it to the headlights. You can probably wire it directly to the headlamp, or you can try doing it through the headlight relay under the hood in the relay box

LotusRenaultF1 said:

Mount them where you want them to be then wire it to the headlights. You can probably wire it directly to the headlamp, or you can try doing it through the headlight relay under the hood in the relay box

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do not wire them directly into the head light. these are not your cars of yesterday. Almost everything is control by relays, transistors through the BCM or other modules, If you wire things like you did on your old cars you're going to fry modules. This is the age of computer technologies, keep up.



This is my suggestion: if you don't fully understand the following before attempting the install have someone who does do the install.


you need a wiring diagram and a standard bosch relay. you're going to have to either find a empty spot in a fuse panel and run your power from there or run your own fused power from the battery. find the control circuit for the headlights and splice into it to operate the relay. The fogs will have to be wired in parallel so make up a wire with 1 into 2 (Y) a leg running to each light. and then run separate grounds for them.


wiring for the relay

fused wire from battery goes to pin 30.
wire from relay to lights pin 87
wire from headlight control circuit goes to pin 86
from ground to relay pin 85
pin 87a not used

Got bored did quick diagram of the foglamp circuit in Paint.


you can also wire pin 85 from the fog relay to the headlamp relay pin 85.

damn ken i wish i had half of your knowledge...lol....i usually just wing it and hope i dont blow the car up...

cost me $37K to know what i know :/

CFCobalt said:

damn ken i wish i had half of your knowledge...lol....i usually just wing it and hope i dont blow the car up...

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No joke, I have a 91' GMC that's kicking my butt. I fried the fuse block and had to rebuild that just to get back to the point where the truck wouldn't run.

Try another battery, get a little battery like a lawnmower battery or something and put a switch on it where you can turn off the lights whenever you want them on, you can put more than one thing on it too.

White Balt, bitch.

white balt said:

Try another battery, get a little battery like a lawnmower battery or something and put a switch on it where you can turn off the lights whenever you want them on, you can put more than one thing on it too.

White Balt, bitch.

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not seeing your reasoning on this.

It was ment for slo

White Balt, bitch.