Pontiac Repair: starting problem, pontiac firebird, thin gs

Question
Hi there, I have a 1989 Pontiac Firebird with a 2.8V6.  Sometimes, after about an hour of driving, the car won't start.  I can hear the solenoid clicking but no starter turnover.  The inside lights and headlights work fine.  Then, after about 30 minutes of resting, the car will start up just fine.  I've replaced the battery and starter and the problem has not improved.  Someone told me that this might be a relay (seperate from the solenoid) somewhere inside the car.  Is this possible, and if so, what is this relay called and where is it located?  Much obliged.

Answer
Hi Ivan:

well it can be a few thin gs. Yes that relay could be the issue this car has a pass key system which is a factory security system and that relay could be the issue i may not be sending full battery voltage to the solenoid to crank the starter. It's behind the dash on the right side. It's barried and not east to get to! what you really need to do here is catch it when it will not start and see what's going on. you need a didgitgal volt meter and when it just clicks have a helper crank the car and you see what you have for voltage at the purple "crank signal" wire at the stsrter motor you shoulfd have at or near battery voltage. same thing withe the big red battery cable at the solenoid. If you have battery volatge then the starter is bad or posssbaly a bad ground cable/ground connection. If you DO NOT have full battery voltage then you have to trace the wires backwards to find where your loosing the voltage. Good luck :)