trailer brake wires - Diesel Forum

dutydave · 11-22-2003, 05:27 PM

Just picked up my 03 E350 Cutaway on Wednesday. Truck was not order saw it does not have the towing package. I found the wires for the the trailer lights on the rear of the truck. Does anyone know if the brake wire is on the truck already or does it need to ran from the front of the truck? How sbout the conection for the brake controler were is the conector located under the dash?

DieselDeaf · 11-22-2003, 06:03 PM

I don't have an 03 but I would assume the wiring is already in plce regardless of a tow package or not. On my 96 the battery feed and brake feed was there at the inner rear frame rail, the battery feed was already hot and the brake feed was there as well,for travel trailers. There should be a plug under the dash that you can connect your brake controller to, you may want to get the harness adapter to make an easy connection. It will have the stoplamp, power, ground and brake controller output feeds already in place.

BoneHead · 11-23-2003, 10:26 AM

Speaking of cutaways.... I used a 99 box ambulance as a parts vehicle when I converted my 75 E100 over to a dually diesel and one of the small remaining issues I have had is with the tail light wiring. I could not find any wiring in the harness (which I used completely in my van) that was a direct feed to the tail lights. I ended up using the trailer harness, but it feeds the turn and brake lights through relays (as far as I can tell). While that works it doesn't work well with the turn signals. The van by itself is OK, but with a trailer (any trailer) hooked up the turn signals are so dim you can hardly see them, especially if the running lights are on. It appears to be an issue where the turn signal is on and off to quick to allow it to light up completely, even though they are blinking at regular speed. I'm thinking that has something to do with going through a relay. If I could fine the correct wires that come on a cutaway to wire the tail lights direct I'm sure I would be better off. I have one section of harness that is behind the driver seat that I thought would have it, but none of them seem to be related to the exterior lights (the dome light wiring is in this section of harness).