Team Chevelle banner
  • Hey everyone! Enter your ride HERE to be a part May's Ride of the Month Challenge!

1 - 16 of 16 Posts

·
Registered
Joined
·
62 Posts
Discussion Starter · #1 ·
Hi,
I am working on cleaning up and organizing the wiring in my engine bay and can't seem to figure out what this one wire is supposed to b do. It is a big red wire that is attached to the starter, on the same terminal as the + battery cable. It then splices together with the big red alternator wire and both wires attach to a third piece of red wire (approx 2" long) which is attached to the horn relay. after searching this forum and looking at the wiring diagrams, I cant figure out what this wire is and what it is supposed to do. By the look of the way the wires are attached, I am not sure if it was a factory wire, or if someone put it in there for some reason. The splices look kind of sloppy so I think that may be the case. Should I leave the wire there, or take it out? Thanks a lot!
 

·
Registered
Joined
·
2,922 Posts
It connects your battery, alternator, and main junction (horn relay) together. The rest of the electrical system is fed from the relay junction.

It's there because it's needed to charge the battery and carry the load of the entire system.
 

·
Registered
Joined
·
163 Posts
Jonny,
I am NOT an expert on car wiring, but I do know a few basics. I am sure someone will correct me if I am wrong, and without more details I can only be generic anyway.

First off, unless you have a smaller red wire at the + battery post attached to the terminal, the electrical needs of the car (other than the starter) are met through that one wire you are talking about.

All electrical needs are supplied by your battery when the engine is not running. So that's where it's connecting to the battery at.... at the starter solenoid.

When the engine starts, the alternator supplies all electrical needs AND recharges the battery. That's why the wires tie in together.

The horn relay was a typical place to make a "distribution" point to send the positive charge down to supply the car's needs. That's why they both tie in there.

That one wire you are talking about carries one heck of a lot of current at times. It can get pretty warm under the best of conditions. With more resistance added from bad connections, you are asking for trouble.

If the connections are not tip top shape, you need to correct that and do it right. I like solder and heat shrink myself, others prefer proffesional crimps.

Steve
 

·
Registered
Joined
·
62 Posts
Discussion Starter · #6 ·
Thanks a lot for the info guys, it is much appreciated. Sorry, I forgot to mention it is a 72 malibu, no A/C. I think I will go ahead and replace that wire just to be safe then. Any suggestions on what type of wire to use that will handle the current without issue? I will be switching over to an HEI as well and correct me if I am wrong but I will need to replace that small red wire that goes from the fuse block to the coil (has "resistance wire" printed on it) with a 14G wire. Also, I read on here that it is OK to get rid of the small yellow wire that goes from the starter to the coil. Thanks again!!!
-Jonny
 

·
Registered
Joined
·
7,762 Posts
The wire you are looking at is the main power wire. It's purpose is to supply the car with 12 volts and to charge the battery. Unless you add extra items to the car, the wire size is fine.
That wire runs from the solenoid B+ (large) terminal to the stud on the horn relay mounted on the firewall. About 6 inches up from the solenoid there is a fusible link. A spongie foam looking thing in the wire. This link must be in the car. If it has been removed, it needs to be replaced. This is the main fusible link that protects the entire car against a major short.
No you don't need the yellow wire with HEI. It's easier to run a new wire, for HEI, from the fuse block to the HEI BAT terminal than to play with the resistor wire. Just tape the resistor wire back.
 

·
Registered
Joined
·
62 Posts
Discussion Starter · #8 ·
Thanks for lending your expertise John. I see a black wire coming off of the horn relay stud that says "16G fusible link" on it in white letters and runs into the bulkhead connector, does this sound correct? Also, the wire coming off of the startert that I asked about before looks a little strange. The first 6 inches or so are a brownish colored wire and then there is a cylindrical connector of some kind that is about 3/4" long and feels like hard plastic or something. Is this the fusible link you speak of? from there on it is the red wire which attaches to the horn relay. I am not sure if this is correct or not, because I know a previous owner had rewired at least a couple other things . Would it help if I took some pictures? Thanks again!
 

·
Registered
Joined
·
7,762 Posts
“The first 6 inches or so are a brownish colored wire and then there is a cylindrical connector of some kind that is about 3/4" long and feels like hard plastic or something. Is this the fusible link you speak of? from there on it is the red wire which attaches to the horn relay.”

Yeah that’s the main fusible link. Not the easiest thing to change but that’s where it is on the 72.
When you do the HEI conversion, one place to get a new wire and HEI connector is here.
http://www.centechwire.com/catalog/accessories/hei1.shtml
 

·
Registered
Joined
·
62 Posts
Discussion Starter · #10 ·
Ok, it's all starting to make sense now!!!! Thanks again John, you're a life-saver. I'll keep you posted on how it's going, although I haven't had as much time to work on it as I would like. I am a college freshman and work part time so progress is often slowed by that. You seem to be a real electrical guru after sifting through a lot of the old posts on this forum. Hopefully one of these days I'll get it all figured out! Thanks again!
 

·
Registered
Joined
·
7,762 Posts
Originally posted by fat jonny:
I am a college freshman and work part time so progress is often slowed by that. You seem to be a real electrical guru after sifting through a lot of the old posts on this forum. Hopefully one of these days I'll get it all figured out! Thanks again!
Nope not me. Just an older guy who's supposed to be working not goofing on the net. Just happen to own a 72 for the last 32 years so I've seen the wire a couple of times.
 

·
Registered
Joined
·
62 Posts
Discussion Starter · #12 ·
Wow, that's pretty cool that you've owned the car since it was new. No wonder you know the ins and outs of it. I was wondering, I have done a few searches on here about the HEI conversion and have seen some say to use 14 gauge and some say to use 12 guage wire to replace the resistance wire. Which one is correct? Thanks!
 

·
Registered
Joined
·
2,922 Posts
14 will carry the current with no problems, but 12 won't hurt anything. Neither is "correct" or "incorrect", the 12 ga. just gives you a little bit of "headroom".
 

·
Registered
Joined
·
2,922 Posts
Centech are good people. I've bought a few components from them in the past. I will definitely deal with them again.
 
1 - 16 of 16 Posts
Top