I have a '05 model F-250 XL that won't start...the engine won't even try to turn over. Ran great yesterday with no problems but I go out this morning and my keyless entry remote won't unlock the truck so I use my key to get in. Then it wouldn't start.

My battery is fine, checked it with a multimeter and the radio, lights, and all other electrical options work fine. I'm thinking it might have something to do with my keyless entry. Since my truck is an XL, the keyless entry must have been added aftermarket, but it looks to be made by Ford Motor Co. (I looked at the module on the panel below the steering wheel. I've had previous vehicles that had keyless entry systems with a "vallet switch" to override the keyless entry and start the vehicle, does this exist on SD's or should I get it towed to the dealer? Thanks.