88 gts won't start

[jarsone]

I have just bought an 88 gts and it seems to start fine in the moring and at lunch, but when driven a long distance, say 30 miles, it won't start. The clutch switch seems to be working fine as the car won't do anything unless it's depressed, but when i depress it, the clock dims, interior lights dim, etc., but no start. I can run a hot lead from the battery to a relay swith and the start cranks no matter what. This was an option but after i removed the after market alarm system (thinking i fixed the problem) all of the interior lights, running lights, and tail lights won't work. The engine was replaced after a wreck the person i bought it from had a couple of years ago. I've traced wires and didn't find anything bare and I'm not a foreign car guy or wiring expert. Any suggestion to get it to start right without the hot switch would be helpful.