We extend an earlier plasma-kinetic model of an inverted V auroral arc structure to include, in a phenomenological way, the effects of electrostatic turbulence with k∥/k⊥≪1. In the absence of turbulence, a parallel potential drop is supported by magnetic mirror forces and charge quasineutrality, with energetic auroral ions penetrating to low altitudes: relative to the electrons, the ions' pitch angle distribution is skewed toward smaller pitch angles. The electrons energized by the potential drop form a current that excites electrostatic turbulence; we consider the specific case of the ion cyclotron mode. The turbulence heats the ion in T⊥ only, thus tending to reduce the differential pitch angle anisotropy between electrons and ions, which in turn reduces the potential drop--an effect of opposite sign to that associated with anomalous resitivity. In equilibrium the plasma is marginally stable, with growth rates and diffusion constants some 2 orders of magnitude below naive estimates. The conventional anomalous resistivity contribution to the potential drop is very small, because anomalous-resistivity processes are far too dissipative to be powered by auroral particles; this is why growth rates and diffusion constants are so small. Under certain circumstances equilibrium may be impossible and relaxation oscillations set in; the time scale for such pulsating auroras is the ion transit time of 6--10 s.