Here's why it's likely happening:
* Faulty Brake Pedal Switch: The most common culprit. The switch itself might be internally shorted or worn out, causing it to send an incorrect signal to the horn circuit when the pedal is released. This is amplified because the release action is often more abrupt than the depression, possibly causing a momentary short.
* Wiring Issue: A short circuit or damaged wire related to the brake light switch could be sending power to the horn circuit when the brake pedal is released. A wire might be frayed, touching another wire, or corroded.
* Bad Horn Relay: While less likely, a faulty horn relay could be malfunctioning and activating the horn intermittently. The brake light switch's faulty signal might be triggering this.
Troubleshooting Steps (Do NOT attempt electrical work if you are not comfortable with it):
1. Inspect the Brake Pedal Switch: Locate the brake pedal switch (usually under the dashboard near the brake pedal). Visually inspect it for any obvious damage or corrosion.
2. Check the Wiring: Carefully examine the wiring harness connected to the brake pedal switch for any frayed, broken, or corroded wires.
3. Test the Brake Pedal Switch (Advanced): You might need a multimeter to test the continuity of the switch when the pedal is pressed and released to confirm if it's functioning correctly. There are online tutorials showing how to test these switches for specific vehicle models. This requires understanding basic electrical principles and safety precautions.
4. Check the Horn Relay: Locate the horn relay (usually in the fuse box under the hood or in the cabin). You might be able to visually inspect it or swap it with a similar relay (if you have a spare) to see if that resolves the issue.
If you're not comfortable performing these checks yourself, take your Dodge Caravan to a qualified mechanic for diagnosis and repair. Attempting electrical repairs without proper knowledge can be dangerous and could cause further damage.
