[meangreen92]

That's a good corrolation. The symptoms you describe, however, almost sound like the relay. They're like 14 bucks or something. I wouldn't buy one, but if I could swap in a known good one, I'd try that before getting a new pump. The relays are different after '90 or '91. If you're really careful, you can remove the cover on the relay itself, and inspect the contact points for corrosion. The exposed coil wire is very easy to mess up.
If it's the original pump though, it is pretty much a sure bet that it's toasted. I replaced mine because it was louder than the engine! What size pump are you looking at?

 

[meangreen92]

The relay should be under one of the front seats. The Inertia Switch is the one in back. I know the 'zone carrys them, I'd bet Napa does too.
I like to get stuff like that from junkyards and parted out cars. Most people don't know what the hell they are, and will let 'em go cheap.