1973 - 1979 F-100 & Larger F-Series TrucksDiscuss the Dentsides Ford Truck
Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.
You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!
I am having brake light troubles. Out back on the passenger side my tail light is acting funny. When I turn my lights on, the passenger side is very dim. It is also dim when I turn my right signal on. When I hit the brakes (with the lights off) it comes on also very dim. When I hit the brakes with the headlights on, the light doesn't come on at all. I took at look at the bulb socket and it seems ok, but only the 'headlight" filament would come on at all, the brighter brake light filament doesn't come on at ever. I a trailer light connection wired on last year and my tail lights have been acting funny ever since.
So, to finally cut to the chase, does anybody have a color coded wiring diagram of the tail lights for a 1978 (F350, if this matters). I'd really like to get my lights working properly.
Sounds like a ground problem. Anytime one light dims or goes out when another light powered from a different circuit goes on, it is almost always a ground problem. The increased current creates a voltage drop across an unwanted resistance in the ground path, often referred to as "ground shift."
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.