HELP!! Coupe wiring

Took the coupe out Saturday since the weather was nice. Just cruising around town no problems.......Got home doing my post ride inspection and noticed a wire split in two along the frame rail. Well the wire from the alt was burnt to a crisp. Okay here's the specs SBC running a real magneto for spark and a one wire GM alt. The magneto once its started makes its own juice that's why they need a separate cut off switch. So the alt just puts a little juice back to the battery and keep the lights bright. There was no fuse in the 10 Gauge wire to the battery from the alt. My question is what size fuse should I use and do I need one? Also the alt is not charging now. I'm sure it needs to be replaced. This sucks I hate wiring its like a black art. Any help would be appreciated!

wish i could help you out but AT LEAST YOUR USING A ONE WIRE.... (stewart knows all about one wires)

I would go with 90-100 amp fuse I doubt your pulling more then that. What you need to find out is what caused the short in the first place.

I got a few questions. do you have a true after market one wire or is it a converted later model? where is the battery? in the trunk? under the floor?
first thing is to yank the alternator off and take it to the parts store to see if it's charging. if it is, cool. if not go ahead and get one. tell them to get you one for a 78 350 camaro. that is easy to remember. come back to the house and on the alternator you will have a stud sticking out the back and a place for a plug on the side. the plug will have two prongs. you want to run a wire off the #1 prong to the back of the stud. it will say 1 or 2 next to the plug. take a new wire and run it off the stud all the way to the plus + side of the battery.
you will have a short wire from the stud to plug and another wire from the stud to the battery. I have never ran a fuse on any of mine. I wouldn't even know what to tell you to get if you did. to me it would lower the current running through it. maybe someone else can put some light on this but I run converted one wires on everything and have never had a problem. make sure you use the biggest round clip that you can find for the stud. make sure it fits the stud and is not hanging over the stud too much but big enough to put a good size wire in it. I'm free this weekend if you want to mess with it. I could stop down. just let me know.

Its a true one wire alt not converted. The battery is an optima red top located in the trunk. After I spliced in a new section of wire I tried the old screw driver on the back to see if it was charging and felt no magnetic pull, so I think the alt is dead. I will take it off and get it checked this week and keep you posted.

Okay, took the alt to Advance Auto Parts. Had to show them how to hook it up and test it. They kept asking what year is it on and trying to look it up on their computer. Finally got it tested and its shot; barely putting out anything. So I did some research on the situation. What I had was a 100amp alt with no fuse. When the alt shorted out it burnt the wire. Painless wiring recommends at least a 50 amp in line fuse when running over 65 amps. Just for this type of circumstance. So I ordered a new King Chrome 65 amp from Speedway Motors. It should be here by this weekend. I might run a fuse just as over kill, better safe than sorry. As a side note I don't have a fire extinguisher in my Coupe. Its one of those things I kept putting off. That has changed due to this small problem. I recommend everybody do the same and know how to use it!

steve knows all about fire ext. the 46 i have he caught it on fire.....

46underconstruction wrote:steve knows all about fire ext. the 46 i have he caught it on fire.....

lol I didn't know it had a hole in the gas tank when I started cutting out the floors. lol but yes you should have a big red fire extinguisher. I have one in almost every corner. but then again I'm a fire bug.

RebStew wrote: but yes you should have a big red fire extinguisher. I have one in almost every corner. but then again I'm a fire bug.

Fire is your friend!!

Got my new alt on Friday. Spent the day in garage on Saturday. Didn't go to the swap meet in Louisville due to the weather. Put the new 65 amp alt on and it works great. I still need to replace the entire wire back to the battery. I don't like spliced wires. Hopefully this will take care of the charging system.

so now u can drive it up this weekend for calvacade, correct?

Maybe! If there is no snow or salt on the road.