1984 GMC C60 What went wrong while sitting?

[Jmh68C10]

I have a 1984 C60 with a 366 gas engine. Truck ran great when parked a year ago but now is getting no spark. Ideas?

[77 C-20 Scottsdale]

Start by checking the wiring. Make sure rats or rabbits have not chewed the wires.

[demian5]

Originally Posted by 77 C-20 Scottsdale

Start by checking the wiring. Make sure rats or rabbits have not chewed the wires.

Make sure the wire from the starter to the coil wasn't eaten.

[geezer#99]

Originally Posted by demian5

Make sure the wire from the starter to the coil wasn't eaten.

It doesn't have one.
It's an hei.

[maxx442]

Distributor cap/rotor contacts may be corroded or oxidized. I'd also check your coil. Could be as simple as a loose ground.

[johnthegreat508]

Decomposed coil. Most likely corrosion of distro of connectors in the ignition wiring.

[cadillac_al]

If you have 12 volts at the distributor then it is the module. They can die anytime anywhere, especially after 30 years.

[special-K]

Corrosion. I'd pull the coil out of the cap and check there, as well as inside the distributor. First try cleaning all that up with Lectramotive. Could be carbon tracks from bad cap.

[andyh1956]

HEI's are notorious for the rotor buttons going bad.

[Jmh68C10]

Anyone have a wiring diagram of the wiring coming out of the HEI distributer? This looks a little suspicious.

[nonstop]

The battery one next to it is still connected, right? That looks like it may have gone to a tach (tach terminal is next to the battery). Is there any chance it was touching ground? May be your problem right there. Try disconnecting it. Truck should run without it.

After looking again, hard to tell from the picture, but if that runs to the battery terminal of the cap, then that is your problem. It needs to be reconnected to the wire from the ignition. What is that heavy gauge pink wire connected to laying across the manifold? That looks like it should be the batter wire for the HEI.