I think you're having trouble getting your question answered because it's a little ambiguous. That's because the DRL-1 module can be used for a bunch of different applications, not just adding DRL function to the front turn signals. One of these other functions is that it can be used to have the front side marker lights flash with the front and rear turn signals while also remaining functional as steady-lit side markers (when the turn signal isn't activated). That's a nicer alternative to the non-module way of making the side markers flash with the turn signals, because by using the module the side markers will always flash in phase with the front/rear turns, never in alternate-phase. If you use the non-module method, by putting the side markers' wires across turn signal + and parking light +, the side markers will flash in phase only when the parking lamps (or headlamps) are
off. If you turn the lights on, the side markers will flash in alternate-phase with the turn signals, which isn't as good particularly in applicaitons where the side markers are also visible to the front.
If you want to use the DRL-1 module to have the front side marker lights flash with the turn signals, always in phase no matter whether the parking lights are on or off, the hookup instructions are
in this article. If you also want to use the DRL-1 module to have a daytime running light function added to the front turn signals, you would need a total of two DRL-1 modules, because each module can only be wired up to do one function, not multiple.
If you are doing the non-module method of having the side markers flash, and installing a DRL-1 to implement daytime running lights, then the only real concern is how to hook things up so the side markers don't light up full time with the DRLs. That's not hard. You cut the side marker light's ground wire, then tap the "bulb" end of the cut wire into the vehicle's turn signal wire
ahead or "upstream" of where the DRL-1 module gets put in line with the turn signal wire. So tracing the wire forward from the turn signal switch on the steering column to the turn signal light on the front of the truck, the tap-in for the side marker wire would come before the DRL module hook-in.
Don't forget to upgrade your bulbs for best results: 5702KA for the front turn signals (super long life for steady-burning daytime running service) and 6XW for the front side markers (7 candlepower instead of the stock 2 candlepower for maximum side-blinker effectiveness).
