Newbie here...just starting with that as I ask my uninformed questions lol. I just purchased a 1986 F250 6.9 IDI. I'm going through and checking what needs attention, and I've come across some items below. Any help with what they are, the severity of the issue, and the fix difficulty would be much appreciated. It seems that there are not really many mechanics that work on these engines anymore, so I'll take the long road of learning to do repair work myself, to an extent of course. Thanks!


This wire has a big gash and exposes the internals. Not sure what it's for.

This line appears to be one that goes from the top driver side firewall area to the rear. I assume electrical?

There seems to be a bolt missing here (see yellow circle). I see the threads, and I assume there should be one there like the one my arrow is pointing to. Does anyone know the bolt size I would need? Torque?

 

As mentioned above.
The first picture of the red electrical cable is your starter cable. Lots of amps flow through that cable. It's best to replace it sooner than later.
The 2nd photo looks like after market wire for strobe lights or something. It's not factory.
The missing bolt isn't a big deal. Go to O'Reilly's and find a bolt that fits.

 

I can't tell what that other cable is from the pic, but the big wire looks like the battery cable is torn down below nearby the starter.

I'm likewise gonna patch up a portion of my cables pretty soon, because the copper below isn't yet corroded, you could try to fix it.

What I do for this type of repair, and will be doing pretty soon myself, though mine if torn up top at near the battery connection, I have a little aluminium sheet metal folded up on the sides like a rectangular cup.

For a big wire repair like battery cables, I will remove clear, and cut it back to expose a straight edge on the insulation, go over the copper with one layer of electrical tape..

Cut a copper or steel, any kind of metal tube or pipe that is appropriately larger than the repair wire.

Put my alum dish on a burner and toss in one or two good brand name glue sticks, qty depends on repair size.

Put cut in half metal tube below prepared cable, pour plenty of glue stick plastic to cover entire bottom portion, wait as a few seconds the glue will flow slower, heap it onto the top of the cable, and press the other half of the metal tube to form the entire clear insulated plastic repair.

Melt more glue than you'll need, you can just leave unused portion in the plate to firm up and reheat it into more flowing plastic next time.

Practice if necessary, battery cables can be hundreds of dollars, so it's worth it if you can swing a fix, if you can't, replace them, because if it touched that frame your truck becomes a large arc welder.

 

You can repair wire insulation with Permatex Liquid Electric Tape. Brushes on. I'd apply several coats and allow to dry each coat. Then wrap that area with electric tape. Use a dab of contact cement on the electric tape end to keep it from peeling back.

 

If the starter cable is that badly damaged I would thoroughly check the other battery cables and associated ground wires. If the damage in the picture is the only damaged section then repair it but if there is other damage or signs of significant corrosion then you might look into options for a new set of cables, especially if this vehicle is one you intend to drive daily and keep for a while. A damaged cable can prevent adequate current from flowing to the starter which can then lead to premature failure of the starter, difficulty in starting, or as already mentioned it can cause a fire. If any of the factory crimp-on terminals have been replaced with the bolt-on style you ought to give them a good cleaning. One of the POs of my truck had replaced a factory terminal with a bolt-on and there was quite a bit of exposed copper that had corroded and wasn't providing a good connection.

 

On closer inspection of your photo of the starter cable it does appear to be dirty and maybe some corrosion. At a minimum clean up the scar, remove any dirt and corrosion. Old toothbrush with some mild soapy water after a primary cleaning with a wire brush. Then after that rinse with water and dry it well. A heat gun or hair dryer prior to applying liquid tape. That should give you a good temporary repair but as was mentioned you're probably going to be replacing that cable at some point.

 

Thanks everyone. Looking at all the wiring and terminal connections, I am going to replace all the battery cables. Is this a straight forward job? Do I need to remove anything to get this done?

Some additional questions:

1. There is a connector going nowhere under the brake pedal (see image). Should that be like that?
2. There is a silver cylinder connected to the radiator, and looks like no coolant tank. What is the cylinder? Something to replace the coolant tank? Previous owner said a new 4 core radiator was put in.

Thanks!

Looks like it's time to replace the battery wires.


From question #1. Not sure what this connector is for.

Radiator and mystery cylinder.

No coolant tank.

 

The previous owner removed the OEM coolant overflow tank to install that giant air filter. Luckily, that small silver cylinder is your aftermarket overflow tank.

 

You have OEM cables. The cast connectors are very good. However they do get beat up by mistreatment. Hammering on with wrenches, hammers...should never be done. Also over tightening them till the nuts are digging into the casting. These type should be cleaned with a battery terminal cleaner, twisted on or off gently and snuggled using the bolt and nut. If it's been over tightened and the nut is mushing into the casting remove the nut and add a washer or two so you can snug the nut without mushing into the casting. To remove loosen the nut and spread the casting with a large screwdriver. You might have to remove the bolt and go in from the side with the big screw driver, wide slotted. It may have been over tightened. If you can twist the connection and it doesn't move it's snug. Good. Anyway the ground cable in the photo looks good. Check it further. The positive side has a split in the insulation. It could be repaired or replaced. Is the starter cranking well? If so your cables are doing the job.

 

If you only have to replace the positive cable then that shouldn't be too expensive. Nice that you have the larger air filter setup--I want to eventually do the same for my truck with the Sidewinder. Since your overflow container is smaller than stock I wouldn't worry about filling the system right to the top. I've ran for years without a coolant overflow and just keep the radiator level a bit low.

 

Here is the negative cable after removing. Huge gash as well. Surprised all the electrical was working.

 

Wow, that is beat up indeed. My 86 has all original cables and they look great. I'm wondering how yours got so beat up?

 

Good question. Well, regardless, definitely replacing all the battery cables. Hopefully it’s all accessible without having to remove other parts.

 

So removing the passenger side positive cable that goes to the starter, I see this elbow and bracket.

1. this bracket was just hanging loose, not sure where it was originally attached
2. even if I knew where it was attached, I don’t think the elbow is coming off of this cable

So my question is, do I even need to attempt to attach this to my new cable?


Not attached anywhere

 

Just a guess here but i would bet that bracket was an attempt to secure the cable and keep it from rubbing. I use a fair amount of "chafing gear" to protect parts. Typically I cut a length of heater hose, slice it longitudinally, and then wrap it around the cable or hose so that any rubbing will first damage the heater hose and not the protected component underneath. Secure the heater hose with zip ties as needed.