NAC Starting Problem

[Eric Langheinrich]

I know this is the wrong list to publish this on, but since my little brother is away at school and I can't be there to help him, I thought I'd at least see if anyone here had any ideas....

He has a 1991 Ford Ranger 4 cyl 5 speed manual. He has started having a problem where sometimes when he turns the key, the starter won't turn or click at all. Generally, after screwing around for a couple of minutes, finally, he would be able to turn the key and his truck would start right up. In the last week, it has stopped working altogether. He turns the key and nothing. 

He has done the following to it now:

1) replaced starter
2) replaced the lead from the battery to the relay.

If he takes jumper cables and connects the battery directly to the relay, the starter turns over with no problem. In order to do this there is a small wire that is removed from the relay first. 

Yes, I know there is probably a bit of detail missing from this post, including where the small wire goes, but since I'm at least 700 miles away from him.

Anyway, again, I'm sorry for posting this here, but I am really hoping someone will have some ideas on what to do next to figure out what's wrong. 

My first thought is that it's either the ignition switch (except that when he turns the key, the radio and dash lights work), or some sort of neutral safety on the transmission.