Trailer wiring

[SOLER]

I'm building a trailer, and need some advice on the wiring. It's a 14' enclosed, and so far I have: tail lights, five red clearance lights on top rear, four side markers, and two top front clearance. Some of the lights have two bulbs in each. There are a total of 19 bulbs in the circuit. How many can I get away with on the 20 amp fuse in the trailer light circuit on the truck? I have blown two fuses so far. I'm reluctant to put a 25 amp fuse in there without knowing how big the wire is on the truck.



My two questions are: How many lights (bulbs) can I run on this circuit? And how big of a fuse can I use in the circuit on the truck?



Thanks



SOLER

 

[tbrudder]

Depends on the wattage of the bulbs. Add up the wattage for each one, divide by 12V, and you get the current in amps. If it's more than 20 (that would be 240W worth of bulbs), that's your problem. If it's less, I think you have a short somewhere. I wouldn't use a larger fuse--they're generally put in to keep the wiring from getting too hot. There's going to be a safety margin built in, so you might get away with using a higher-amperage fuse, but then again you may not.



--Ty

 

[y-knot]

You did not give the lamp wattage, so it is impossible to give you and answer. I know you are building this thing yourself, but your trailer is no different then the other 2-3 million trailers running around as we speak. To illuminate your trailer right, there are Federal and State guidelines that should be followed. They specify the placement of all lights and you will need to follow the their guidelines, for all homebuilt trailer will need to be inspected prior to the state issuance of a certificate of origin. Most small clearance lights use 194 or 94 lamps, they have very small draw and the number you gave will be fine. Good luck

 

[bombero]

If I was building a trailer I would separare the brake, turn & taillite from all the marker lights. Most travel trailer have those things hooked up thru the seven prong plug outlet. I think that is wrong. You need to isolate all the markers. Put them in a separste circuit om a simple toogle switch under the dash. I did that with my92CTD. Worked fine. I hate towing somewhere and the hwy required lights during the day. Here in Calif lot of roads have that requirement

 

[bmoeller]

If need be, you can use the marker light circuit to trigger a relay. This will take the load off the switch and truck wiring.