Q: When I try to start my truck, the lights work but no crank.

First, we need to make sure the signal wire to the starter is properly connected and the power cables are attached properly. I have seen many situations where the signal wire is loose or the connector is broken and the same for the power wire. If these check out ok, then check to make sure the signal is present at the starter when the key is turned to the start position. If there is a signal present and sufficient power is available, you may have picked up a faulty starter. If there is no signal present, there is a problem on the ignition side of the circuit. Consider hiring an experienced technician like one from YourMechanic who can come out for a closer inspection of the vehicle to run a few tests in order to offer a more personal diagnosis of your no start situation.