Truck won't start
 

We have a 1992 GMC. It has power but won't start. There is no sound when we try to turn it over but it has plenty of power. Push in the clutch and you get nothing

When you say plenty of power you mean all the lights, horn, etc. are working right? You might have a bad start switch which is on the top of the clutch pedal.

Truck won't start
 

We have two switches that hang over the clutch pedal and have actually tried changing both of them. We don't know what the second one is for and it receives no power. We think it might be for cruise control. At a loss, as we have bypassed both of the switches and have gotten nowhere with it. :confused: As far as power yes all the lights, horns and everything are working.

Just because the battery has enough power for lights does not mean it has enough to power the starter. I suspect your battery is weak, will not hold a charge, the fact that if you charge up the battery and can start the car sometime means its not the starter and if the car runs once started means its not the alternator either.

You didn't say what year! How old is the battery? Have you checked the connections at the battery?
You said: "I have a 1992 GMC." Explain please!
Do you mean battery power when you try to start, or engine power while driving!
If truck is driveable,most auto parts stores can check the battery.
does the noise stop when you turn your key on? if so, battery may be the problem!
good luck!

I dont think there will be a problem in battery as lights and horn are working properly.There should be a problem in clutch or there must be some thing wrong in engine.