1998 Subaru Legacy will not start sometimes?

The battery cables at the battery were a good place to start. Just two more things for you to inspect.
1) Follow the two battery wires to their connections, start with the negative one first as it is likely the problem. You are looking for a loose connection where the cables are bolted down or a fair amount of corrosion at the same place. It is a good idea to unbolt and clean them at the engine block and body even if they are tight, based on the age of your vehicle.

2)If the concern still persists check the voltage drop on both cables with a volt meter and key in the off position. The reading should be less than .2 volts. You are checking for internal corrosion that may not be visible from the out side.

One follow up question: How long between starts does the vehicle sit?

Good Luck,

Hi Bill,
Glad you checked the terminals at both ends for corrosion. I was wondering if you checked the resistance in the cables yet? Is this what you meant by clean? You also stated repairs are up to $600 but I don't know what parts have been tried yet.

If you have eliminated the cables here are some other ideas.

1) This is tricky unless you are in a shop with help at hand. Carry a small ball peen hammer with you in the car. Next time it acts up, someone will need to hold the key in the crank position while you tap, not bang, the starter solenoid. If it fires up you have an intermittent starter failure.

2) Starter relays. All relays can be checked by exchanging it for a similar one driving a different device. If your problem goes away the component using the defective relay will act up intermittently. These are fairly inexpensive, and since I don't have a picture of your fuse block to see if you have a similar one, buying it is a cheap way to check.

Good luck.