I have an '04 XE without the tow package. I am wondering if anyone knows are the "trailer Tow 1 and 2" relays supposed to be installed on the truck at the manufacturer or are they "accessories"? I have never came across a full size pickup that you couldn't just plug in and go if the wiring was already there.

It has been discussed a lot here. 04 XE do not have the harness under the dash for controller. Do a search on "relays", you will find more then you want to know!

There is some conflicting info on this, it seems that some XE's have the brake prewire and some don't. It appears that late build 04 and the 05 XE's have the brake prewire. But regardless, the wiring for the relays and the lighting are present but the relays are not. The relays come with the hitch as part of the tow package. If you buy the OEM trailer hitch it comes with both relays and the 7-pin plug. Hope that helps.