Click on image for the lowdown. 
====
| | | Forums66 Topics128,154 Posts1,056,851 Members48,456 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Jan 2020 Posts: 431 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 431 | No clue how it happened, I went to start my truck yesterday, and started to see smoke on the driver's side, and it was fighting me to start. Somehow, I've managed to melt my brown alternator wire.  I have not had one single problem with my wiring. The only thing I can think of is, when I put my new speedometer the other day, maybe a wire got pinched up in the dash or something. I'm going to dive into it after work today, but man that really annoyed me. | | | | | Joined: Jan 2020 Posts: 431 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 431 | I went out and pulled the fuse block from the firewall, and 2 wires, next to each other, have had the jacket on them completely burned off. They are:
1. the brown wire returning to the fuse block from the alternator, and
2. the brown wire going to/from the accessory ignition terminal on the ignition
I will be ordering a new harness, but my question is, how could I have prevented this? I have the original groundstrap going from the cab to the transmission housing, and I have another 10 gauge wire going from the starter over to the actual frame rail. I had not had any issues with things set up this way. Should I add additional grounds? And if so, can you tell me from/to locations? Man this stinks. | | | | | Joined: Apr 2005 Posts: 7,441 Bolter | | Bolter Joined: Apr 2005 Posts: 7,441 | Such occurrences are a real concern for the antique vehicle community. A 64 year old truck has been exposed to all sorts of weather conditions and of course critters that like to chew on wiring. Heat deteriorates wiring insulation and just moving the wire to get to something else can cause the insulation to fall off. Could you have done something to prevent this from happening? Probably not given where the short was located. Count yourself lucky that it happened while you were there instead of in the dead of night when you were awakened by the fire truck sirens. As you have figured out, a new wiring harness is in order. You got this!
Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
| | | | | Joined: Jul 2000 Posts: 2,200 Insomniac | | Insomniac Joined: Jul 2000 Posts: 2,200 | I read some of your earlier posts.
Looks like you have a V8 with automatic transmission and a (new?) Speedway wiring harness. Recently, you have been working on the brake light. The truck was was running fine until you wired up the brake light and now you have burnt wires. Most drivers put their foot on the brake when starting the vehicle so I suspect the brake light is shorted out.
Does that make sense?
Gord 🇨🇦
----
1954 1/2 ton 235 4 speed
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | This may be a moot point or your question does not need an answer since a new harness is going in.... but....without reading all your posts to see what you have done: 1. I see you have a 350 installed. 2. A "brown wire" or brown wires, tells us nothing about where each end goes. Colors get changed and if you have installed an alternator, we don't know what the brown wire does. There is a sensing wire and a exciter wire. 3. Don't understand this: "the brown wire going to/from the accessory ignition terminal on the ignition" . 4. Like I said, does not matter now probably. Keep in mind for future questions. Wiring is a very specific item. It has "to-from" as it is called. Each "TO" and each "FROM" must be fully identified by it's component and the components terminal number or name. I.E. Ignition switch ACC terminal. 5. Consider buying a universal pre-wired fuse panel type harness. The ones where you mount the fuse panel on the inside of cab, on the upper left hood hinge bolts. Take out all wiring intact if you can. Take off all firewall fuse blocks. Don't throw any of it away. Removing the steering wheel is a good thing to do. The overall process is a great DIY project. I've done many TF's. Don't know what electrical gauges you have. The harness kits don't support ammeters, so dump it.Adding grounds? The wires fried because something got grounded. Your grounds seem OK 
Last edited by bartamos; 06/01/2021 11:50 PM.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jan 2020 Posts: 431 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 431 | Such occurrences are a real concern for the antique vehicle community. A 64 year old truck has been exposed to all sorts of weather conditions and of course critters that like to chew on wiring. Heat deteriorates wiring insulation and just moving the wire to get to something else can cause the insulation to fall off. Could you have done something to prevent this from happening? Probably not given where the short was located. Count yourself lucky that it happened while you were there instead of in the dead of night when you were awakened by the fire truck sirens. As you have figured out, a new wiring harness is in order. You got this! Man you aren't kiddin' on having it happen at home! The sad part on this is, it was a universal harness. The original one for this truck was long gone. That's why I'm trying do what I know best on this truck, but the grounds ALWAYS seem to be the unknown factory for me. Thought I had them covered this time, so I'm at a bit of a loss on what happened. | | | | | Joined: Jan 2020 Posts: 431 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 431 | I read some of your earlier posts.
Looks like you have a V8 with automatic transmission and a (new?) Speedway wiring harness. Recently, you have been working on the brake light. The truck was was running fine until you wired up the brake light and now you have burnt wires. Most drivers put their foot on the brake when starting the vehicle so I suspect the brake light is shorted out.
Does that make sense? Thanks! Yep, I follow the logic that you have laid out, but I had not even gotten to hooking up the brake lights to anything with power just yet. I was just waiting for the new brake light switch to show up so I could go to that next. All that was hooked up was the basic wire components to the engine, and a tach. Everything had been fine otherwise. | | | | | Joined: Jan 2020 Posts: 431 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 431 | This may be a moot point or your question does not need an answer since a new harness is going in.... but....without reading all your posts to see what you have done: 1. I see you have a 350 installed. 2. A "brown wire" or brown wires, tells us nothing about where each end goes. Colors get changed and if you have installed an alternator, we don't know what the brown wire does. There is a sensing wire and a exciter wire. 3. Don't understand this: "the brown wire going to/from the accessory ignition terminal on the ignition" . 4. Like I said, does not matter now probably. Keep in mind for future questions. Wiring is a very specific item. It has "to-from" as it is called. Each "TO" and each "FROM" must be fully identified by it's component and the components terminal number or name. I.E. Ignition switch ACC terminal. 5. Consider buying a universal pre-wired fuse panel type harness. The ones where you mount the fuse panel on the inside of cab, on the upper left hood hinge bolts. Take out all wiring intact if you can. Take off all firewall fuse blocks. Don't throw any of it away. Removing the steering wheel is a good thing to do. The overall process is a great DIY project. I've done many TF's. Don't know what electrical gauges you have. The harness kits don't support ammeters, so dump it. Adding grounds? The wires fried because something got grounded. Your grounds seem OK Thanks for the info. Yep, it's a 350. I'll ask more questions before I try to install harness #2. | | | | | Joined: Jan 2000 Posts: 591 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 591 | the same thing happened to me once. The speedometer cable shield is grounded. In my case, I somehow got the speedometer cable touching a 12V source, I think it may have been the ammeter terminal. In any case, after taking care with the routing of the speedometer cable it never happened again.
don | | | | | Joined: Jan 2020 Posts: 431 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 431 | Thanks all for your input!
Long story short, I managed to pinch the brown wire coming off of the 2 prong connector (tab 2) of the alternator. It ran down the passenger side of the engine, and got pinched by the starter and my ground wires. I never even saw it down there when I was recently updating my ground wire connection.
HRL was key in helping to isolate the issue. You guys are the best!!! | | |
|
|
