When you decide to install LED bulbs into you car, you need to know the right size and select the desired color. Next thing to know is that most vehicles use a Thermal Flasher unit to control their Turn Signals. Most Thermal Flasher units are generally not compatible with LED lights without a resistor installed with them. Why you Ask?
Today, halogen bulbs are most often used for headlights and fog lights, and their increased light output increases driver visibility in darkness and inclement weather. Halogen bulbs are a variant of the traditional incandescent bulbs that have been used since the early days of the electric light. The bulb is either evacuated (has a vacuum) or filled with an inert gas to keep the filament from oxidizing.
Posted by Nassry H. | 2004 Ford Excursion
"These look great and the install is pretty easy. So far, no trouble with anything. Only suspense is LED lifetime and if the plastic can hold up to the elements. Only time will tell."