87 Iroc 5.7

Occasionally, when starting, the engine will partially turn over and then nothing. No electrical at all. No headlights, interior lights, ignition, etc. Battery tests fine. This happens maybe once every3-4 months. If I unhook the battery for about an hour then reconnect, everything comes back on and it will start right up. I've checked all grounds, even added one just in case, and nothing seems to affect it. All fuses are good, I only drive it when it's sunny so water getting in something isn't an issue. I'm lost on this one. Any ideas?

Steve

 

Check your battery connections at the starter

Key is the interior lights go out as they are fed by 12v constant

 

Ok, I'll check the starter connections. You make a point about the lights not working and they are on a continuous 12v feed. What is it about the starter connections that would disrupt this and then reset after I unhook the battery? Is there a master kill switch in the system somewhere that can be reset? I know, it's a dumb question, but this is weird. I'll let you know what I find with the starter wires.

Steve

 

GM put the power distribution point as the battery cable lug on the starter. By unhooking the battery you must fiddle with the cables, potentially bringing the lost contact back

Next time it does this, simply tug on the cables and see if anything happens

 

OK, feedback time. I replaced the wire from the battery to the starter. Surprisingly enough, the in dash voltage meter became steady, it used to be a little jumpy, the engine seems to run a little smoother, and the headlights are brighter. Only time will tell if this fixed the original problem, but this is definitely and improvement.

Steve