'84 GMC No Start - Electrical Problem

[COPO-RAT]

So I dig my '84 GMC SWB 1/2 Ton out to get it ready for a couple legs of the power tour (Long Hauled it on the Power Tour in '07)....finished up the Vette brake swap up front and went to start it and.........nothing........I mean NOTHING! I have headlights and taillights, no brake lights, no hazards, no turn signals (with key on), no power at the neutral safety switch and the battery is up. 12.65V at the fuse box in the 'batt' slot.
Any ideas?

[TDS-MN]

I did experience a similar issue with my truck. i can't recall if all of the same systems were powered or not, but I did have lights, and nothing when I turned the key.

In my case, it was a wire feeding the junction block on the firewall, just to the passenger side of the brake booster. One of my wires on the bottom side had corroded and fallen off the block. After reconnecting that, everything fired back up. I never did pull out the wiring diagram to see what was connected to that wire, but I'm thinking that there may have even been a fusible link there, too.

Good luck!

[tylervalo]

Something happened to me, the large ground on the back of the firewall was loose. Tightened it up and no problems since.

[COPO-RAT]

Thanks for the feedback guys.

TDS-MN,
I checked that junction and nothing is loose or broken off. I have power on both sides.

tylervalo,
Where is this ground behind the firewall that you are talking about? I will go hunt for that!

BTW,
I've replaced the neutral safety switch and the starter solenoid. Ignition switch is next unless it's that ground tylervalo is talking about!

[COPO-RAT]

Replaced ignition switch today.....truck fired right up, was super stoked......let it run for a bit then shut it off......tried to restart after I shut it off and nothing.......same as before I changed ignition switch.........any thoughts?