Fusible links

[colby721]

I recently inherited an 85 Silverado with a 454 big block (and propane system) I’m not very expierenced in turning wrenches.

Long story short my grandpa was going to boost the pickup off (batteries were completely dead) and hooked the booster cables up backwards (he’s 83 and was by himself and it was getting dark) and after he realized they were backwards the truck has 0 activity when you turn the key. I put a brand new battery on it and the clock in the dash work and the dome light but that is all. I found 2 fusible links on the starter solenoid, but isn’t there 2 more on the fire wall? I talked to a mechanic and he said the fusible link with the purple wire is what I need to find. Like I said before I found the ones on the starter but I cannot find the one on the fire wall that’s on the purple wire. I did find the purple wire coming out of the fire wall but I can’t seem to trace it down to the starter. Any help would be appreciated!

 

[Bextreme04]

I recently inherited an 85 Silverado with a 454 big block (and propane system) I’m not very expierenced in turning wrenches.

Long story short my grandpa was going to boost the pickup off (batteries were completely dead) and hooked the booster cables up backwards (he’s 83 and was by himself and it was getting dark) and after he realized they were backwards the truck has 0 activity when you turn the key. I put a brand new battery on it and the clock in the dash work and the dome light but that is all. I found 2 fusible links on the starter solenoid, but isn’t there 2 more on the fire wall? I talked to a mechanic and he said the fusible link with the purple wire is what I need to find. Like I said before I found the ones on the starter but I cannot find the one on the fire wall that’s on the purple wire. I did find the purple wire coming out of the fire wall but I can’t seem to trace it down to the starter. Any help would be appreciated!

The terminal block on the firewall in your last picture should have the fusible link going off towards the driver side.

 

[colby721]

I’ll be sure to look at that when I get off of work, the links on the solenoid don’t look burnt up to me do they to you? And Thank you!

 

[Dave M]

I’ll be sure to look at that when I get off of work, the links on the solenoid don’t look burnt up to me do they to you? And Thank you!

Never mind how they look from the outer, they are designed to fuse inside, and the silicon sheathing doesn't leave melted wires exposed.

 

[colby721]

So update on the project. The terminal on the firewall has fire on both ends. The wires from the baggers have power. However the purple wire that attaches to the solenoid still has no power when you turn the key. You can hot wire it but you have nothing else (radio heat/ac etc.)

 

[Dave M]

So update on the project. The terminal on the firewall has fire on both ends. The wires from the baggers have power. However the purple wire that attaches to the solenoid still has no power when you turn the key. You can hot wire it but you have nothing else (radio heat/ac etc.)

Is this truck an automatic trans, from where l sit it sounds like a possible issue with the neutral safety switch circuit. If so, at the bottom of the colum inside, there would be a plug with 2 wires, a purple/white (which is power from the key to crank the engine) and a purple wire which then goes through the firewall plug down to the starter solenoid. Check for voltage at each point.

 

[colby721]

Is this truck an automatic trans, from where l sit it sounds like a possible issue with the neutral safety switch circuit. If so, at the bottom of the colum inside, there would be a plug with 2 wires, a purple/white (which is power from the key to crank the engine) and a purple wire which then goes through the firewall plug down to the starter solenoid. Check for voltage at each point.

It is in fact an automatic transmission. My dad did mention something about a neutral safety switch

 

[75gmck25]

The neutral safety switch is mounted on the column, and it’s easy to use a jumper with two spade terminals to jump it and troubleshoot. Just pull the plastic connector off the switch and put the jumper into the plastic plug terminals. That will tell you if it’s the NSS switch itself or just the switch adjustment.

It could also be a broken ignition switch rack, which is harder to replace. The electrical part of the ignition switch is mounted low on the column, just below the dash. When you turn the key it moves a small toothed “rack” mated to the back of the switch, which then moves a small rod running from the key down to the electrical switch. That rack is made of cheap pot metal and it can crack or break. The replacement is cheap, but requires quite a bit of column disassembly. They usually stock them at the auto parts store, or you can try an online supplier like this one. https://www.steeringcolumnservices....ac/ignition-actuators-and-rack-gears-tilt.php

Another possibility is that your cab has settled on the rubber supports and that has thrown off the shifter adjustment. You may need new cab supports, and/or a linkage adjustment.

 

[Dave M]

The neutral safety switch is mounted on the column, and it’s easy to use a jumper with two spade terminals to jump it and troubleshoot. Just pull the plastic connector off the switch and put the jumper into the plastic plug terminals. That will tell you if it’s the NSS switch itself or just the switch adjustment.

It could also be a broken ignition switch rack, which is harder to replace. The electrical part of the ignition switch is mounted low on the column, just below the dash. When you turn the key it moves a small toothed “rack” mated to the back of the switch, which then moves a small rod running from the key down to the electrical switch. That rack is made of cheap pot metal and it can crack or break. The replacement is cheap, but requires quite a bit of column disassembly. They usually stock them at the auto parts store, or you can try an online supplier like this one. https://www.steeringcolumnservices....ac/ignition-actuators-and-rack-gears-tilt.php

Another possibility is that your cab has settled on the rubber supports and that has thrown off the shifter adjustment. You may need new cab supports, and/or a linkage adjustment.

Could be as stated, but let us keep it simple for the moment and try to pin point the exact problem first.