at the risk of stating the obvious...
Originally Posted by hulon131
88 Ranger had no problems then 2 days ago started blowing headlight and turn signal fuses. What would cause this?
This is caused by the circuit drawing power in excess of the fuse's rating.
Q1: Do you have the correct fuse in the circuit? Using a smaller than recommended fuse may result in the fuse blowing when the circuit is otherwise operating normally. Using a larger than recommended fuse is unwise, as it may lead to a larger problem (fire!) in your electrical system.
Q2: Do you have a short in your electrical system? Any short in the electrical system will cause the circuit to draw power in excess of the fuse's rating, causing the fuse to blow. The short could be caused by physical damage to parts of the wiring harness, or by improperly wired accessories tied into that circuit.