Posted By: Ronnie Ray New Guy Needs Guidance - Mon Sep 09 2019 08:52 PM
Just got back to the site after several years of life. I would greatly appreciate some guidance on how to go about a complete rewiring of a 1946 Chevy 3/4 ton pickup. I'll be change to a 235 12 volt system. Living in the Paci fic Northwest, a good defroster, heater and windshiled wipers are the top priorities. Wiring to pull a utility trailer is of course, a must.
ce a must.
I want this truck to be my get around town weekly driver for the rest of my life so I will to go a little extra to get thing right.
Thanks in advance for your help.

Ronnie Ray
Posted By: bartamos Re: New Guy Needs Guidance - Mon Sep 09 2019 09:29 PM
First thing to know is that it is pretty simple. Buy a wiring harness. I recommend one with prewired fuse panel. I like the ATO fuse panel. From there it's follow the instructions and use the original wiring diagram also, so you learn what you are doing. I don't know your expertise or experience, but don't at all be intimidated by wiring.

I don't know what "ce" is

Read the 12V conversion in our "TIP" section. You will need a ballast resistor.

There are three main bundles to route and tie. Care should be taken to make the route and bundle look good. If there are inner fender terminal boards, I would eliminate those.

There are VERY few wires on an old truck.

The defroster and heater are mechanical items for you to sort out/rebuild/buy. The wiring is just the blower motor.

The wipers are all mechanical if they are vacuum. Heater and wiper questions are for another post.

The three main bundles are:
1. Front lighting/gauge senders/horn
2. Rear lighting
3. Dash/switches/gauge/cab
There will be a few "ignition/charging" wires. Some may not be part of a harness.

Take pictures of all wiring as it exists. All the routing, inside and out. Under chassis and under hood. If this is your first time, those pics will help you as you go. save all the connectors and wiring accessories for ref.

Decide where you want the fuse panel. Firewall, inside cab, upper left is a good place if possible. Sort out/lay out the harness with a few tie wraps as a general layout.
When you get that far, you will have more questions or if stumped, Happy to help.
In general: Everything has a fuse or fusible link. Everything has a switch. If you have a turn signal switch, follow those instructions.

I would not worry about trailer wiring. I would "tap in" after finished with all wiring.

Sooner or later we will need to know your plans/upgrades, if other than 12V conversion.
1. Generator or alternator
2. Foot start or other
3. Ammeter or voltmeter
4. Turn signal switch or not (dual filament bulbs)
5. Pertronix or other than stock distributor.
6. Other upgrade accessories from original.
Posted By: coilover Re: New Guy Needs Guidance - Tue Sep 10 2019 05:34 AM
Do not make the mistake of buying a 22 or 24 circuit wiring harness because the $140 12 circuit harness from Speedway is all you need. As was stated these trucks have very simple electrical systems. I would ditch the generator and go with an alternator mostly because I'm cheap and generator/regulator parts are way more expensive plus the alternator has way better output at low rpm. If connected to a trailer the extra electrical power output is handy. Electric wipers are a near must for trailer pulling. On high humidity days in the winter a defroster won't clear the windshield but turning the a/c on clears it instantly, something you might consider.
Posted By: Rusty Rod Re: New Guy Needs Guidance - Tue Sep 10 2019 03:12 PM
I've rewired a few vehicles and repaired wiring on a lot of others.

The biggest problem I'm having on my current vehicle is that the previous owner (who used a nice Ron Francis harness) crimped the end connectors on with a cheap crimping tool. Several connectors have pulled loose. I usually crimp the connector, solder the end and cover it with shrink wrap (AFTER I"M SURE of what I'm doing). I sometimes leave a few loops of wire when I'm building something and have a temporary crimp only on the end..... just don't forget to go back and redo it when you get closer to the finish line.

He also cut pretty much every wire as short as he could. Some of the components are in so tight, that other components need to be removed to get at them. I wouldn't leave loops of wire everywhere, but leave enough slack to be able to move stuff around a little.
Posted By: Ronnie Ray Re: New Guy Needs Guidance - Tue Sep 10 2019 04:15 PM
Thanks for the tips. They are greatly appreciated.
Posted By: Ronnie Ray Re: New Guy Needs Guidance - Tue Sep 10 2019 04:18 PM
Good to know. Thank you
Posted By: Ronnie Ray Re: New Guy Needs Guidance - Tue Sep 10 2019 04:20 PM
I will remember that technique. Thanks
Posted By: Mr. Dane Re: New Guy Needs Guidance - Sat Sep 14 2019 02:35 PM
all i gotta add is that the wiring can seem stressful and complicated, if this happens, straighten out all the wires on a table. believe me it helps alot
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