Originally Posted by Louie
Explain. I see people using lower 4th brake light on trucks and SUV all the time without incident.
I don't think he is saying not to have a 4th brake lamp, but that a light unit specifically designed to be a fog lamp is not the proper light to use as a brake lamp. I agree somewhat becuase the fog lamp is a particularly birght lamp for low visibility conditions not to be used on a clear night.
In practice an OEM rear fog is usually not "blinding", and using it as a brake light is probably better than the tools in Audis and Volvos driving around with the rear fogs blazing 24/7/365. Americans can't be trusted with fog lights hahah
But really do you want a left side offset brake light? A rear foglight on the left indicates to pass left, a brake light only on the left indicates you have a bulb out ;-)
Also this has already been hashed out, you can't use the OEM rear fog switch on the stalk, it is a momentary switch that signals the BIU to turn on the rear fog. It was never determined if the US BIU would run this, and what pins the input/output is on. So if you do this just get a separate switch...