Here's what you should do:
1. Disconnect the battery completely. This is crucial to prevent further damage. Make absolutely sure both positive and negative terminals are disconnected.
2. Assess the damage (visually, if possible). Look carefully around the steering column and firewall for any obvious signs of burning, melting, or damage to wires or components. Take photos.
3. Call a qualified mechanic or roadside assistance. This is not a DIY repair. The damage could be extensive and involve:
* Blown fuses: Check the fuse box (there may be multiple) for blown fuses. However, the problem likely goes beyond simple fuse replacement given the symptoms.
* Damaged wiring: Reversed polarity can melt insulation and short circuits. This requires careful tracing and repair by a professional.
* Damaged ignition switch: The ignition system is a likely candidate for damage.
* Damaged control modules (ECUs): These are sophisticated computer modules that control various vehicle functions. Reverse polarity can easily fry them, resulting in high repair costs.
* Damaged alternator or starter: While less likely given the symptoms, they are possible points of failure.
4. Do NOT attempt to jump-start the truck. Jumping it with the wiring potentially damaged could cause a fire or further damage to the electrical system.
The dash lights and horn working suggest that some circuits are still functional, but the main power distribution system is likely compromised. Professional diagnosis and repair are absolutely necessary. Ignoring the problem could lead to more extensive and expensive repairs down the line, or even a fire hazard.
