Brand new battery, dies in a few days. Also truck won't start after heavy rain. And my radio got fried some how(think it was directly wired in, not sure)

Wiring in the truck is a disaster, looks like a bunch of stuff has been rewired and they left the old wiring in place and just added new wires, there's as many wires running that aren't connected to anything as there are actually connected wires.

I've found some wiring diagrams and I'm planning on removing all the old wires and checking all the current wires to make sure they're good.

I have all the diagrams in the Haynes manual as well as this one that I found on here.

Anyone have tips about this process? First time dealing with itm

Included pic of some of the craziness in my truck.

 

If it comes down to it, rewiring entire truck is not rocket surgery. My wiring was dangerously bad, so I am using an EZ Wire harness, and it has been pretty smooth going. Way better than putting up with all the old junk. You get to use all new stuff which is really nice. 150 dollars for the harness is a lot better than trying to fix worn out stuff.

 

First thing, I'd try to locate a donor at a good (cheap) junkyard to get as many pieces of stock wiring with connectors to graft back into the system. If you can get it back to stock or nearly stock configuration, it makes tracing wires and troubleshooting much easier.

Nothing is worse than all black (or any single color) wires.........I had a Harley like that once. It makes everything much more difficult. Take it wire by wire. If you skip around it is easier to make an error. Label everything if you have to change colors. Good luck!

 

You want to protect the new battery from discharge. An automotive start battery doesn't like getting deeply drained, this will ruin them after just a half dozen cycles or less.

So first charge it back up for a day or so at a nice slow 2 or 4 amp rate asap, and keep it unhooked till you're positive (heh) the wiring is straightened out. See the firewall where those wires are exiting? There's no grommet installed there anymore, so the wires can eventually rub or chafe. Bad deal. That's the kind of thing you'll want to fix as well. You want to avoid especially a fire.

You'll need a test light and a good voltmeter, and a wiring diagram. Pull out all the nonsense that was installed and trace out each wire and check for continuity etc. Connect an ammeter in series with a battery cable and battery terminal. Check the parasitic or "phantom" drain.

On older trucks the total current draw should be Zero. In later years 50 milli-amps is considered acceptable or, at least normal. 1000 milli-amps = 1 amp btw.

 

With every new to me vehicle, I go on "hack patrol" - IDing all OEM wires and tracing all those that are not OEM. If the non-OEM wires are not correctly installed, I'll trace and disable them or remove them completely.

Look for "twisted & taped" connections, duct tape, T-taps, crimp connectors, wire nuts, and other questionable crap. I'll pull on the wires of crimped connectors to see if they pull out easily.

If you know that something was just a quick repair, then solder or use uninsulated barrel crimps and seal them with heat-shrink. For example, it is very common to use T-taps for trailer wiring. Remove it!!!

Get back to basics and study the wiring diagrams...... verify the starting circuits, headlamps, turn signals, brake lights, and horn. That's all it really needs. The rest is "extra". Meaning, they are not critical to drive around the block. Pull fuses if you have to....

Once those systems are verified then move on to wipers, fan motor, dash lights, radio, courtesy lights, and such.

Examine all light sockets for corrosion, clean, and apply dielectric grease.

Verify all grounds are tight and actually form a ground. In fact, I recommend extra grounds such as bed to frame, cab to frame, inner fenders to frame, and core support to frame.

Verify that the engine to cab ground is present and tight... just that one ground is very critical. I forgot to attach it and my electric fuel pump would prime when I turned on the headlight switch. Very weird... Discovering it disconnected, I reconnected it and everything was back to normal.

 

X2.
The correct advice.

 

And maybe to simplify things, work on one harness at a time. Learn what each harness is, and where they connect to other harnesses.

 

I had this problem on a couple of vehicles. On my Dent, I finally traced it using an amp meter. It was the dome light plunger switch on driver's side.

Edit: Sorry, should have said how I did it. Make sure everything is turned off. Set your multimeter to MV, and touch the leads to each side of each fuse. If you get any kind of reading, there's an amp draw on that circuit. Once you've narrowed it down to which circuit it is, then you can start looking at those connectors, switches, and wires.

 

The best thing you can do is focus on removing all the old wires ONE system at a time.. Get all of the PO's bs out of the truck. Looking at the overall picture of the issue can be over welming but these old pickups have minimal wiring compared to anything modern.

I always start with the ignition first then branch out to charging, starting ect ect...

Keep the battery unhooked for now because spent energy=heat and unattended it could start a fire.

 

The other advantage to leaving the battery disconnected is that if you discover that it still drains, you know it's the battery that is bad in this case.
Bad alternators and voltage regulators can drain a battery too, but it's usually overnight and does not take a couple of days.

Otherwise, what they all said already. Good advice.
Too bad about the old Dura Spark module on the fender. But hey, there are lots of ignition alternatives for our trucks these days. Lots of choices.

Paul

 

My advice as a career industrial electrician/troubleshooter, you will end up spending more time (and probably money) trying to locate and correct these issues. Unless you have to have this vehicle up and running now, I suggest park it and start reviewing the companies that make replacement harnesses. Painless Performance, American Autowire, Centech, Letric Limited, epictec, Kwik wire, and Ron Francis to name a few. Depends on what you are looking for. You can spend $1100 for a complete kit that is a direct OEM replacement, or design your own (price depends on your needs), or do what I did, I went with Centech wiring. They are probably in the middle. My cost ended up being around $550 with tax and shipping. Jim at Centech knows these trucks and will call and talk to you. He will put together a package based on your needs. It's not a direct replacement. Not all of the connectors are provided most are but not all. If you want everything you need provided then Centech isn't what you need. I think painless and Ron Francis have a package that contains all the connections, but they are a bit pricey.

​​​​​​The total time you will invest searching for these issues will be frustrating and leave you with serious doubts if it's fixed or not. My suggestion is to go ahead and buy that peace of mind, and replace your wiring. Is it a big job? Yes. Can you do it? If you can follow a basic wiring diagram, don't get in a hurry, I am sure you can. I would suggest getting a copy of your trucks original wiring diagram, you can either purchase a set of service manuals (I have a set and would gladly send you anything you need) or look on Fordification.com and see if yours is there. The harness will come with instructions, but it's best to have a diagram as well.
I'm just starting a re-wire myself, I had planned on doing it this past weekend, but family issues kept me from it. Be happy to help if you decide to do it.

Brandon










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