* Short Circuit: The most likely culprit. A short circuit somewhere in the rear air suspension system caused the fuse to blow. The short could be in the wiring harness (chafed wires, rodent damage), a faulty air compressor, a malfunctioning air spring, a leak in an air line, or a problem within the air suspension control module. Replacing the fuse without fixing the short will just blow another fuse. A qualified mechanic needs to locate and repair the short circuit.
* Faulty Air Compressor: The compressor might be drawing excessive current, causing the fuse to blow. It could be failing mechanically or electrically.
* Air Suspension Leaks: A significant leak in the air lines or air springs will cause the compressor to run constantly, eventually drawing too much current and blowing the fuse. The leak needs to be located and repaired.
* Air Suspension Control Module: The module that controls the air suspension system could be faulty. It might be sending incorrect signals, causing excessive current draw.
* Wiring harness issues: Damage or corrosion in the wiring harness can cause intermittent shorts or open circuits that may not always blow a fuse immediately.
* Wrong Fuse: Though you mentioned replacing the fuse, double-check that you've used the correct amperage fuse. Using a higher amperage fuse is dangerous and could cause a fire.
In short: You need a professional mechanic to diagnose the underlying electrical or mechanical problem causing the original fuse to blow. Simply replacing the fuse is a temporary fix at best and potentially dangerous. Continuing to drive with a malfunctioning air suspension system is also risky.
