Hello, I am new to the forum. I have a 1989 Chevy Suburban with a 6.2L. I am currently experiencing some type of electrical problem. When I attempt to start the vehicle I am unable to get it to fire. It's turning over and wants to fire, but it doesn't sounds like it has enough battery power. When the vehicle is jumped it fires up the majority of the time. I have checked thay both batteries are good, I have both cleaned off battery connections and installed new battery connecting bolts.
Any thoughts?

How about the leads to the starter, they may be worn out and now have to high of a resistance? I would check all the wiring for the whole starter loop and make sure that none of them are damaged. Could be the problem. and hopefully is because that would really be an easy fix.

Also welcome.

May also be a worn out starter .

After checking all leads and wiring I found nothing. The last day I tried to start her up was last Wed, before heading out of town. When I got back on Monday, she fired right up???
It must be a loose connection somewhere then right?
I also have another idea. I recently rebolted some king of fuel switch that is hooked up to a solenoid. The switch is activated by the throttle...When the pedal is stepped on one can see the switch being activated...Any idea what the switch is actually called?
I have also noticed that when my glow plugs are activate, before I start up, the switch is activated.
Here's my theory: There's a loose connection in the switch that wasn't allowing it to activate before starting there by preventing fuel from entering the engine to start it up?

Any thoughts?

Thanks, Bill