Running Fogs With Highs
 

I was wondering why the dealer could not tell me what federal DOT law they would be breaking if they enabled my fogs with my highs. I guess its because there is not one. I just got off the phone with this lady and asked her to email me what the law says. Now it may be illegal in some states but I know its not in AZ & NM.



Hello Tom,
In response to your question regarding running the high beams and fog lights simultaneously, there are no Federal regulations that prohibit those functions from being active at the same time. Federal Motor Vehicle Safety Standard (FMVSS) No. 108 (the vehicle lighting standard) only regulates performance specifications for lighting equipment. The state DOTs would regulate use.

Best Regards,

Cassandra Hayden

Safety Compliance Engineer

U.S. Department of Transportation

National Highway Traffic Safety Administration

Office of Vehicle Safety Compliance

PH: 202-366-2190

E-mail: cassandra.hayden@dot.gov

I was under the impresion that is was the number of lights on at the same time, not which ones but that is what I was told and don't even know if it was a federal or a state law.

terb: Good job researching it. Dealer in Kenai had said the same thing to me. I believed them. Than a couple of years later contacted our Alaska DMV. They said the dealer was full of it so it is not a problem up here either.

Duckhunter is right. It is the number of lights you use that is the issue. In Iowa, you cannot use more than four "auxiliary lights" (Code 321.420). States usually model their laws after those of other states. I expect most states are similar. Manufacturers must follow federal laws when making your truck, but you won't find anyone who would enforce this particular law that Cassandra spoke of, on the streets of Yourtown, USA, Just the state law regarding number of auxiliary lights.

so is this an option that can be turned on at the dealer to run the fogs with the high beams?

HotRod

In Wisconsin we can have a maximum of four forward facing lights.

hotrod929: I got confused the last time I got involved in that discusion. Here is one of the threads on the subject. https://www.dieseltruckresource.com/...ight=fog+light

I know on my 05' that they say (I don't really know who they are now you mention it) that the use of high, low and fogs would/could overtask the electical system. That is why they have components like the Brite Box and a couple others they sell. They use the controls but get power directly from the battery so they don't put the amps though the wiring. I am still thinkng about purchasing one myself. I know when I lived in Kodiak Alaska I wish I would have for the winter driving!!