* Bad Power Window Switch or Wiring: The most straightforward explanation is a faulty power window switch or damaged wiring in that specific circuit. Since this is separate from other electrical systems, a localized issue is probable. Check the fuses related to the power windows *first*. If the fuse is blown, something is shorting that circuit. Replacing the fuse might temporarily fix the windows, but the underlying short needs to be found and addressed.
* Ignition Switch Problem: The ignition switch is responsible for supplying power to various components, including the starter motor and power windows. A failing ignition switch may not provide sufficient power to the power windows while still allowing other accessories to operate. This is a common failure point in older vehicles.
* Faulty Battery Cable Connections: Loose or corroded battery cable connections can cause intermittent electrical problems. Poor connections can provide enough power for some circuits (lights, radio) but not others (high-draw components like the starter and power windows) that require more current. Clean and tighten the connections at both battery terminals and the starter.
* Starter Solenoid/Relay: The starter solenoid is an electromagnet that engages the starter motor. A malfunctioning solenoid might not receive enough current from the ignition switch to operate, thus preventing starting, but other circuits remain unaffected.
* Wiring Harness Issues: A damaged or corroded wire within the main wiring harness could impact the circuit feeding the windows and starter. This is less likely than the above, but it's possible, especially if the truck has seen significant environmental exposure (rust, water damage).
* Body Control Module (BCM): While less common, a failing BCM (or related relay) could be responsible. The BCM manages many electrical functions in modern vehicles. A fault here could cause seemingly unrelated electrical components to fail.
Troubleshooting Steps:
1. Check the fuses: Start with the power window fuse(s) first, then check other relevant fuses (starter-related if there is one).
2. Inspect battery cables: Clean and tighten all battery connections.
3. Test the power window switch: Try different switches to see if the problem is localized.
4. Check for voltage at the power window motor(s): If you have a multimeter, check for 12V at the motor connectors with the window switch activated. No voltage confirms a wiring or switch problem.
5. Have the battery and charging system tested: A weak battery or alternator could cause similar symptoms.
6. Inspect the starter solenoid: Look for any obvious damage or corrosion.
7. Have a mechanic inspect the ignition switch: This requires more advanced tools and knowledge.
If you're not comfortable working with car electrical systems, it's best to take your truck to a qualified mechanic for diagnosis and repair. Ignoring the problem could lead to more significant damage.
