Hi Everyone, I am cleaning up a spaghetti wiring creation by the former owner(s) of my 74 K5 Blazer. I am trying to confirm if there are 2 fusible leads that go to the battery connection of the starter/solenoid or just one. I have one fusible lead that appears to be broken off, the other frade and corroded that connects to the starter/solenoid. Also, what gauges would those fusible wires be. Thank you all for your time.

 

Yes ones broken. Seeif the current rating is marked in the link. My 78 has one in the metal tube near the starter.

If they aren't marked, Check a wiring diagram or find the max current for the WIRE (not the circuit, fuses are to protect the wire not the load usually) and buy a new one and solder it in.

Dont use plain copper wire to make your own, copper wire has too low resistance and too high melting point for fusing and never put fuses in headlight circuits!

 

Thank you for your reply, I couldn't find markings on the broken dark brown fusible link, wire gauge size on the primary side of 16ga. and the plastic sleeve indicates 10.5. The red fusible wire link, wire gauge size is 12ga on both sides of the sleeve. The sleeve indicates 12.1, the markings were to worn to read any numbers. I think once I get this figured out, I am going to put these fusible links in better place in case they need to be dealt later instead or having to take the starter off.

16ga

12ga

12.1 on red wire sleeve

10.5 on dark brown sleeve

 

Fusible links aren't rated in amps. They're rated for wire gauges. For example, a 12ga. fusible link is made to protect a 12ga. wire. And you want them as close as possible to the power source (the starter lug, in this case) so they protect the entire circuit. If you put it, say, next to the fuse box, you would have the whole length of wire between the starter and the fuse box that wouldn't be protected in case of a short circuit.

 

Ok, that makes since. Thank you.

 

X2 on keeping the fuseable links as close to the device as possible. The link is for safety. If your starter draws for some strange reason a lot of amperage the link will burn in two. This keeps your vehicle from catching fire. Remember when those k5's came out and have always wanted one. They were and still are an excellent vehicles. When you are young, so many expenses to keep your checkbook low.

 

Just a thought. Are there new wiring harnesses that can be bought as a whole? That harness looks shot to me. I guess that the remainder and all the stuff under the dash is in no better shape than what is on your pictures. These harnesses are a fire waiting to happen.

 

The wiring harness(s) will be replaced. I am cleaning up the starter/solenoid wires and alternator to battery for now. This K5 had a stereo system that was top of line back then and the wiring installation is definitely not what I would done. I just want to get it running and drive it to work the bugs out. After that "fun" begins. Thank you for your suggestion, it is appreciated.