The slimline dish you mention is not SWM, so you need to reset your receiver to multiswitch SL-3 as you noted previously. As Chip states, you probably want to set the receiver setting to 1 for just tailgating. This way you only run one wire from your LNB to sat 1 input on your receiver. Since you are looking at a tailgating setup I would use the receiver meter and a portable TV for your aiming. Just be sure the satellite setting is set to 101 (which is where it typically starts) on your meter screen.
Now, for aiming. Go to dishpointer.com and set the Satellite line to 101 W DIRECTV 4S... Next enter your location on the first line. You can fine-tune your exact location by moving the green spot to exactly where you are located. This gives you the azimuth and elevation you need to align your dish. I don't know where the elevation marker is on a standard dish, but you should see a red line on the back part of the elevation markings. Use this line to align with the elevation markings embossed in the bracket.
One of the most important steps is to make sure your mounting pole is exactly vertical. None of the other steps will work well if you skip this critical step.
You do all your initial alignment on sat 101. So use the settings you see on the dish pointer site to do you basic setup. I set the elevation first to the number you see on the dish pointer site. It seems to work easier for me. Tighten the elevation bolt enough that the dish will not move while you do the azimuth. Next rotate the dish on your pole until the LNB arm lines up with your compass setting. As Chip noted, keep your compass away from anything metal since that will mess up your setting. Now tighten the pole bolts a bit to keep the dish from moving on its own.
At this point you should see some signal showing up on the meter display. Move the dish slowly left to right and back for the highest reading on the meter. When you get that position, tighten the pole bolts to make sure the dish will not rotate any more. Now move the dish up and down slowly for the best signal reading for the elevation. When you find that position tighten the bolts holding the elevation bracket. For tailgating this should be good enough to get you a workable signal on 101.
Now set your tilt to the offset value you see on dishpointer. Now, you can change your meter satellite setting to 99 or 103 to check for the best tilt while you rotate the tilt on the dish. But, I find that for my RV use it is usually good enough to just set it to the values on dishpointer and leave it alone. I would only mess with it if you have dropout problems with any HD channels.
If you follow these simple steps you should be golden.
Enjoy
