The Stovebolt Site Forums The Shop Area The Electrical Bay Replacing Wiring Harness; 6V w/ Gen...Need Suggestions!

1950, 3100 w/ original 6v system (generator). No after-market anything.

I am about to replace all the wiring in my truck. It still has the original cloth-insulated wiring. I bought my wiring harness, grommets, extra bulbs, new tail-light assemblies, new battery box and hold-down. My existing headlights, and front running lights/turn lights are in good shape so I'm just going to change the bulbs in the turn lights. Somebody in the past put on some chintzy trailer lights for the rear lights and mounted them up high. It looks, well, chintzy so I'm putting on the "original-like" tail light assemblies that are held by brackets that bolt on the bottom portion of the bed (on either side of the tailgate). I bought all my stuff from Classic Parts and am so far very pleased with what I've received.

Do y'all have any suggestions of the best order of operations for this project?

Here are some of my initial thoughts:
1. Take lot's of pictures.
2. Label EXISTING wires and make note of what they are connected to. IS THIS NECESSARY???
3. Take old wiring out.
4. Put new wiring in.

Now, there is a whole helluva lot of stuff that needs to happen between #2 and the finishing of this project. But since I've never done this, I don't know what they are...in essence, I don't know what I don't know. I'm trying to figure out if I should just pull out all of the old and then start putting in the new? Or should I work in sections? Should I pull the new wire and have it along-side the old; disconnect the old, re-connect the new, then yank the old? That seems logical to me, but seems too easy and seems to make too much sense...

Do I work from front to back? Or start from the ________ (fill in the blank with battery, or dash, or any other component) and work my way out? Do I remove my gauges or just try to disconnect/re-connect while everything is intact in the dash? Are there things that should be removed just for ease of working (like the seat, or other things?)??? If and when I have a leftover wire, how will I know if I "missed something" or if there is just extra wire for other future accessories? And if I have an extra wire, do I cut it out our do I leave it and just keep it disconnected for future use?

Do I have to follow a certain order of operations when I hook things up and energize the system for the first time?

Any help y'all have to offer is greatly appreciated. There ain't very many wires in the whole darn truck so it can't be that difficult of a project, but I don't want to burn something up just out of pure ignorance and stupidity...

Thanks,
KINGLONESTAR

Not so tough to do. Use a bit of string on the wire to the dome light. That will be what you use to pull the new wire back in to place. Use an "original" type harness. It will have what you need and should fit. Remember you have a 6 volt system so the "original" harness should have the right size wire in it. Use the diagram in the shop manual and take your time. "Natural" color is sorta tan, not white and not yellow. Enjoy the adventure and get an "ohm" meter. It will be your best friend. Turn on circuits one at a time. Try using a lamp battery for testing. It will provide 6 volts but not so much current that you will burn anything up. Get new grommets for the fire wall. The old ones will be too hard to work with. Only the fuel gauge is delicate and you will find those wires easily enough. Let us know how it works.

I'd take pictures of how every thing is routed and clamped then rip it all out. No need to label existing wires. New harness wires should be marked or color coded. Remove gauges and speaker grill for better access. Get some brass thumbnuts from the hardware store to remount gauges. Lay the harness in the truck with wires going to the general area where they attach. Lay it in open clamps where applicable. Start any where you want and take your time. Inspect for correct hookup as you go. Meaning after you wire headlights, compare it to the diagram. Same for gauges, etc. After everything is hooked up go back and tighten clamps and dress it up where needed. Don't install battery until everything is installed and compared to the diagram.

Take your time, do it right and have fun doing it. If you get frustrated back off and get your thoughts together.

Good luck.

As I embarked on wiring my COE, I felt a bit intimidated, as you apparently do. It turned out to be a very enjoyable process. In addition to the above suggestions, let me add;

1) First, disconnect both battery cables. Not a bad idea to remove the seat cushion before starting, as you will spend some time under the dash. Remove the gauge cluster and headlight switch from the dash, drop them down so you can access them easily (cluster will remain attached to the temperature capillary tube--don't break that!)then remove the original harness. No need to worry about the old wires, assuming your new harness is properly marked.
2) Start by threading the new harness through the firewall grommet, from the inside. It goes through the grommet easier than the other way or you will be pushing cluster light sockets through the hole. Turn your attention to the headlight switch and gauge cluster. Be sure you have connected the gas gauge correctly, you don't want to fry your gauge if you have reversed the wires. You should have a smaller ignition harness that goes through a separate grommet. Get that connected to the ignition switch and ammeter before replacing the switch. Note Steve H's suggestion to use the old dome light wire as a assist to get your new wire through the A pillar. The lights to the speedometer and wires to ignition switch can be be accessed adequately without removing them.
3) Go to work on the engine side of the firewall, attaching the proper wires to the voltage regulator, terminal blocks for the headlights, brake light switch, dimmer switch and horn.
4) Wire your tailight(s).
5) Before hooking up the battery, test the positive and negative cables with an ohm meter. If all switches are off and you have no resistance, you messed up and you will want to find the cause before you hook up and melt your nice new harness!

Let us know how it came out.
Kent

6v system w/ generator and you say you've bought everything from Classic...did you buy their $150 harness? If so, the instructions are perfect and they make wiring a super easy task. I saved mine and labeled what color corresponds with which number just in case I ever need to refer to it and the numbers have worn off.

The only thing I'd add to what everyone else said...replace the main power cable (1ga) and both ground straps while you're at it.

My blog entries on rewiring and main cables - http://rustyfiftyone.com/category/electrical/

So far so good...here's an update.

Removed all the old wiring from stem to stern. Removed all the gauges, headlight switch, ignition switch, dome lamp assembly, headlights, chicken$h!t trailer lights that a previous owner had put on, and run lights (well, ONE of them...more jeryr-riggin' to undo on the other one...). Cleaned up any connection terminals and removed as much rust and corrosion as possible. All my contact points looked relatively good for a 64 year old truck.

Ran wires to headlights and re-installed them. Mounted new tail-lights. Pulled new wiring harness to all appropriate general locations. Completed connections for headlights, generator, starter/coil, stop light switch, all connections to head light switch (re-installed in dash), and domelight.

I removed my gauges completely because I am going to refurb them and make em all shiny and purty. Upon inspection, looks like they were all fine except the fuel gauge. All others work so I am just gonna replace the fuel gauge and clean everything else up.

Had to order some things that I didn't think of on first order...decided to go ahead and just replace the whole assemblies for the front run lights...chrome was boogered up badly and the aforementioned jerry-riggin' that was used to mount them will be eliminated by installing new...plus, I need the double filament anyway to add turn lights in front. Had to order the gas tank sending unit...didn't know I would need it separately from main wiring harness. Bought new dimmer switch, all dash bulbs, turn signal flasher and stuff for my wipers.

Gonna be swamped with honey-do's this weekend but hope to get a little more done soon.

Question for bluemeanie...in the wiring harness, there is an extra bundle of pink, white and brown wires that had no connectors on them, and then a little baggie of connector ends. Since the wiring harness basically stops after you drop it down the firewall to go under the cab, can I presume that those extra wires are to run to the tail lights? They aren't numbered and there isn't anything else that is missing wire...there were a couple of wires that had numbers on them that did not have a corresponding line in the instructions. What are those for?

Did discover that the horn in my truck is not original, nor is it in the original place. Not sure if I want to find an original replacement, or just splice some wire on and hook up to the one that's in it...it's mounted on passenger side firewall where heater core penetrates. Like the sound of it, so probbly gonna do the latter.

This has been more fun than I anticipated. The simplicity was very comforting...i was overwhelmed when I originally reached out to yall last week but I was just over thinking it. Thanks for the tips and pointers and more importantly, the encouragement! Instead of looking at my repairs as a "have to" I decided to look at them as "GET to's." I feel blessed to have the ability and opportunity to work on a true American classic.

Till next time...

P.S.
I hope to figure out how to get links to my pictures up hear, and get me a blog going...

KINGLONESTAR
'50 3100

Kinglonestar,
Thanks for the update. You state "This has been more fun than I anticipated". That is well said. Certainly, there are times I have been frustrated working on these old trucks,but these are far outweighed by the sense of satisfaction of success and pride of accomplishment. I am not a mechanic but I have had a blast learning about these Chevrolet trucks.

Kent

Hope to finish wiring everything up this weekend but not sure I'll have time.

I'm afraid I may get stuck when it comes to wiring the front running/turn lights, and the tail lights, and the turn signal switch. Starting to feel overwhelmed again so Im hoping that once I get started things will clear up a bit.

My turn signal switch has 8 wires coming out of it, 2 red, 2 gray, 1 each of yellow, green, light blue, and black. The instructions that came with the harnes don't show that many wires...hoping I can figure it all out and avoid buying a new turn signal switch.

Something is weird about an 8 wire switch. What brand and model is it? Is it new or was it in use on the truck.

I wrote a tech tip about figuring the wires out on an unidentified turn switch. That will help figure out what the extra wire is for.

Beige or Brown is for the fuel tank sending unit
Orange is dome light
Purple is tail lights
...and I have a bundle under the dash of pink, purple, light blue, dark blue and white that are for the turn signals which I have not yet wired up or installed.

I can check more thoroughly or dig up my wire diagram later this weekend.

The extras with numbers are for if you're using a 7 wire vs 5 wire turn signal switch, I think.