Conversion of 5 Wire to 4 Wire Taillight system for Towing
Posted: Tue Feb 24, 2015 11:28 am
There are often threads on other bus forums that discuss this subject. Indeed there is an active thread on BCM right now.
In 2009 I experienced my upteenth failure of a commercially available converter (photo below).
That prompted me to fabricate a homebrew converter made with automotive style relays. I had observed information/systems built by Craig Shepard, Sean Welch, and Jack Conrad. Ultimately I documented my conversion in an article published in Bus Conversions Magazine. I have uploaded that article on our website: http://eaglesinternational.net/category/articles
As background information, Eagles (and most buses) have turn signal lights separate from the brake lights. This results in a five wire circuit. Virtually all trailers and cars have the turn signal lights combined with the brake lights (4 wire system). As a result, a converter is required. The circuit designed with relays is much more reliable than most commercial converters. It is fairly easy to construct and the parts are fairly inexpensive. Indeed, the original Eagle relays can be used.
The article has two wiring diagrams. I have attached the diagram I made for my system.
In 2009 I experienced my upteenth failure of a commercially available converter (photo below).
As background information, Eagles (and most buses) have turn signal lights separate from the brake lights. This results in a five wire circuit. Virtually all trailers and cars have the turn signal lights combined with the brake lights (4 wire system). As a result, a converter is required. The circuit designed with relays is much more reliable than most commercial converters. It is fairly easy to construct and the parts are fairly inexpensive. Indeed, the original Eagle relays can be used.
The article has two wiring diagrams. I have attached the diagram I made for my system.