Another question just to ask to increase the posts here.

I am wanting to install clearance lights on the roof what is the best way to measure for 5 lights and get the spacing correct.

 

I had heard of someone getting center to center measurements and then just mounting them after making a quick template of the bottom of the lights.

I have also heard of someone just semi free handing the locating of them.

I think really that it would be up to you the owner to determine where you want them really

 

There is a DOT ( department of transportation) standard
The outside 2 are marker lights, and mark the corners.
The inside 3 are ICC lights. Most are spaced evenly on the cab, it becomes important when it is a box, or area that is raised above the cab

 

I have my lights just need the time to install them. But at the moment a working air conditioning is the priority!!