Hi I'm new to this forum and need some urgent help. I recently replaced the starter on my 79' k10, and hooked everything up correctly until I got to my battery. I was blinded by the fact I was about to finally have my truck running that I hooked the terminals up backwards. I went inside to start the truck, then saw a steady stream of smoke coming from the starter location and at the terminal junction on the firewall. Now my starter won't even click. My other electronics work like wipers and lights but no starter. I was wondering if I blew my fusible links or if it's something else. Any info will help THANKS!
I guess I should have read the OP more closely. If you had head/parking lights
and ignition switched components (like wipers, radio, etc) that would indicate that power was available into the cab on both main feeds - and so the fusible links were all still intact.
The feeds to the H/L switch (and other exterior lighting, horn/dome, courtesy lights, clock, etc.) and the ignition switched components are on two separate circuits.
1. The feed to the H/L (and related components) is protected by just one fusible link - down at the solenoid.
2. The feed to the ignition switch (and the alternator BAT terminal) is also protected by a link located just above the solenoid. But that feed has an additional fusible link. It is located between the firewall junction block and where the common lead splits off into two branch circuits - a few inches away from the JB. One side of the branch goes through the firewall and up to the ignition switch. The other side goes to the alternator.
If, after the incident, you still had power to the headlights
and also power to ignition switched equipment, that means both main feeds - that pass through the main harness connector at the firewall and into the cab - were hot.
If the only noticeable issue is that the starter won't engage and crank, it's possible that the problem is with the starter. First check whether power is being supplied to the solenoid when the ignition switch is turned to START.
The solenoid has two terminals that are used with your model year:
The big one - labeled "B" for battery - has 3 leads connected to it. The thick black cable (battery positive) and two smaller red leads with the fusible links.
It also has a small terminal labeled "S" for start. This terminal post will have a thin purple lead connected to it.
When the key is turned to START, power flows from the ignition switch, out through the firewall and down to the "S" terminal on the solenoid.
After you have straightened out your fusible link situation - and you are sure that power is available into the cab - get a helper and check for voltage on "S" when the key is turned to START.
If you see 12 VDC at "S" with the key in START, that would suggest that the starter/solenoid suffered some kind of damage when the battery was cross-connected.
