howdy!

[222DBFL]

First off, you need to get the bottom of that antenna as close to the roofline as possible, you have chosen a bad mounting spot IMO, and it is probably why you aren't getting any replies. Also your whip (antenna) should be total 108" or as close to this as possible. First you need an external swr/watt meter before proceeding any further. Radio shack sells thems for 40 dollars. This is a must, doesn't have to be the radio shack meter, but some type of external swr meter is needed. Next You need to either add a 6" riser or a 6" pot belly spring, and remount that antenna somewhere different. I am not sure all the mounting locations you have, but I am sure there are Better choices. You need to go over your whole antenna system ensuring that all coax, connections, and the antenna are good. The coax and connectors can be checked with an ohm meter, the antenna system checked with at least an swr meter. You want the antenna to have metal and as much of it as possible, under your antenna, rf travels along metal, your antenna placement probably has the rf riding on the tool box or off the back end of the truck, either way no good this way. Get that antenna up and above the roof line of the truck. Also, all connections made on the outside of the vehicle should be weather proofed with at least electrical tape. They do make weather proofing butyl and self augmenting tape for this as well. Water and connectors don't mix well.
But IMO, I would start with getting an swr/watt meter, my vote is for the radio shack meter as they aren't expensive and are pretty accurate for the money. Second, try to find a stainless steel 6" pot belly spring, the more HD the Better as it will keep you whip straight as you travel at highway speeds. Next replace the coax that you are using with some good rg8x and good connectors if possible, not needed if your coax and connectors are good, but is an upgrade from the current coax I see. Rg8x and amphenol PL-259 connectors would be on my list as well though if possible. And also a different mount and mounting location for your antenna to get some metal directly under it so it has an adequate ground plane for the rf to travel along. Don't be intimidated, it's not they hard to do everything I have listed. And it will make a difference. With a good antenna setup and the right conditions, you should be able to talk more than 5 miles. I talk to several people over 50 miles away almost daily on ssb. Granted it's not am, but I can talk pretty far on am as well. It all boils down to your antenna system though, without a good antenna system, you are Pi Pi'ing into the wind!! Good luck with resolving the issue with your truck and god bless.