Trailer Option - Backup Lamps

[kramttocs]

What is the standard practice or your thoughts here?

The factory Trailer Option has the trailer backup lamps spliced directly into the truck backup circuit. Just like the stop and turn signals. Alternatively the trailer running lights are on a relay and the hot 12v circuit is a dedicated fusible link.

I've never had a trailer with backup lamps but am adding them (really flood lamps) during my 22ft equipment trailer rewire.
Via a quick google search it sounds like newer truck have a backup lamp relay.

I can either add a relay to the truck and rewire my 7 pin on the truck or I can add a relay to the trailer that would use the hot 12v circuit in the 7 pin (same as breakaway battery) with the factory backup lamp wire as the trigger.

Some pros and cons to both but want to hear from you guys before I settle on one.

[Gary Lewis]

I think I'd add a relay to the trailer.  That way whatever truck you pull it with will take advantage of the relay.

[kramttocs]

Thanks Gary.
That's the direction I was leaning - I wonder what Ford's intention was since I don't believe the truck backup circuit gauge is very heavy and I wouldn't feel comfortable using it even with leds.

[Gary Lewis]

I don't know what they were thinking.  Doesn't make sense to me.

[85lebaront2]

Gary Lewis wrote

I don't know what they were thinking.  Doesn't make sense to me.

The 1996 PDC I have in Darth has separate fuses for the trailer stop and turn lights and the running lights are fed from the marker lamp system (DRW has a separate feed for them through a relay even back to the original 1986 wiring) I modified it so I have a set of relays, L & R stop and turn, running and reverse and battery charge. The battery and reverse light relays are in an auxiliary relay box, I used one for the 4 wheel anti-lock brakes so I have the stop and turn also.

I went into the PDC and cut the wires from the turn signal switch to the two 10 amp fuses for L & R stop and turn trailer lights. I used them to power the relay coils and pin 87 of the Bosch relays then goes back to the PDC and through the fuses. This way the load on the truck flasher is always the same and I can actually hear and feel the relays with the hood open. Relay box is on the back of the PDC bracket and everything plugs in rather than being hard wired.

Since I have a 1999 Crown Victoria lighting control module, the flasher circuit is built into it.