1990 f150 battery drain

[67Terror]

I'm having problems with the battery on me f150 draining. The battery is new and just tried replacing the fuel pump relay which seems to be a common problem with these. It starts fine if you charge the battery but within a few hours of it sitting it's totally dead. any help would be appreciated

thanks
Jeff

[RACEME]

First disconnect the alternator and see if it still drains. They sometimes get an internal short that causes this. The next step is to do an amperage draw test. You have to hook up a volt meter that is capable of measuring amperage. Then you pull one fuse at a time until the amperage draw goes down to almost nothing. That will tell you what circuit is causing the problem.