All Hummer models are equipped with a fuel filter warning lamp. The lamp is in circuit with a sensor mounted in the filter.
The purpose of the lamp is to alert the driver when water, ice, or wax buildup occurs in the filter.
Lamp illumination can be intermittent or continuous depending on the severity of water or wax buildup. In most cases, continuous illumination of the lamp simply means it is time to drain the filter. However, a continuous lamp plus engine stall or restart problems may indicate a plugged filter or fuel lines.
Intermittent illumination of the lamp indicates that water is accumulating in the filter. In this instance, it is only necessary to drain off the water at the wheel house draincock.
