I just replaced the voltage regulator on my 97 F150. The battery light was flashing intermittently. Steve's right as usual. I have 145K on mine and the brushes were worn out. AZ said they didn't carry and alternator and Pepboys had the regulator without the brushes assembly. Got one at Ford for $81 and it's all fine now. Only wish I could have replaced just the brushes. Probably would have been MUCH less.