We've got an 87 Iroc-Z. My son and I are trying to get her back on the road. When my parents first gave him the car it ran fine. I took it to town one day, parked it, got my stuff and went to go home and nothing happened when I turned the key. Long story short and a lot of troubleshooting we found one of the fusible links had burned. Replaced it, tried starting it again, burned it again. We have replaced the starter, the ignition control module, and the ignition starter switch. Continued to happen, burned the link every single time.
I think we have the issue traced to the thick red wire that runs from that fusible link thru the firewall and up into the dash, but that's where I'm stuck. I can't find where it goes once it enters the dash cluster of wires without removing the entire dash.
Its got a reading from wire to ground, can't remember what exactly, so I'm assuming it's shorting to ground every-time we turn the key to start it.
With a new fusible link in and everything hooked up we can turn the key and all the lights, fans, everything comes on until we go the final point to start the car.

Any help y'all could give would great!!!

 

The link shouldn't burn instantly. It should take a few seconds to get hot enough to burn. It sounds like you have a high draw to begin with and the starter is just pushing it over the edge. I would fix the link and see if it is getting hot with everything connected, not on, then turn things on one by one and see if it is getting hotter. Or pull all the fuses and put them back one by one with a clamp on ammeter and see what is pulling current.

 

 

If I read this statement correctly , it's when you put the key to the start position that the fusible link melts ?

If so , your next check should be to unplug the neutral safety switch and disconnect the purple wire going to the starter's "S" terminal . Use your ohm meter to see if the purple wire shows shorted to ground or not . If so , find and repair the short . If not , check the yellow wire from the neutral switch and see if it's shorted , and check the neutral switch itself for a short to ground . Look especially for areas of botched/butchered wiring , places where someone may have been cutting/splicing wires for things like an aftermarket alarm/remote starter

PS , you will most likely read continuity on the red wire to ground without removing any fuses because things like the radio's memory draw power all the time and will show up on the ohm meter .

 

If you look at the lower right hand side of this drawing you'll see that your starter's crank circuit is very simple , the ignition switch , a yellow wire , the neutral switch (or clutch switch if manual shift) , a purple wire , and then the starter's solenoid , connected with a few connectors along the way . Circuits can become a lot less intimidating when broken down to their basic components and then troubleshot from there

 

You've got a dead short in the Big Red Wire that is protected by that specific fusible link.

Instinct tells me, you won't find the fault on the factory wiring diagram, unfortunately. The factory does a generally pretty decent job of protecting all that sort of thing. More likely, someone has had his d*** skinners somewhere in your car's wiring at some point in its life, "improved" it somehow, and that "improvement" is now bare metal with hard battery on it, that is touching the chassis someplace.

Follow the Big Red Wires under the dash, and I'll bet you'll be able to find the "upgrade" that the PO installed. Remove it, re-connect the wires that he sodomized with an uninsulated crimp splice and solder, and wrap it REAL GOOD with rubber splicing tape and then regular electrical tape over that. Then replace the fusible link, and all should be back to normal.

 

Sofa , with all due respect , if I'm reading this statement correctly from the original post it sounds as if the link doesn't blow till he hits the "start" position on the key . If this is correct , then the short can't be in the red wire , and must be in the yellow or purple wire (or neutral switch) since the link only blows when he actually goes to crank the starter .

 

Yup, sorry, you're right, probably not the Big Red Wire. I should have read more closely. More likely, either the starter circuit (yellow from the ign sw to the neutral/clutch safety sw, then purple to the solenoid), or a Big Pink Wire (ign). Both of which are common victims of "improvements".

 

well what your saying is IMO, when you crank the engine that F Link blows . so my guess is the wire from the ignition switch to the tranny switch park/neutral ..I have had shorts under the dash area.. sharp metal so I put tape around all the wires and or loom so the wires do not get shorted out .

on these GM did not cover all the wires so it will happen..