Hey everyone! It’s been a long while since I’ve been on while I was between trucks (kids and a house will do that to you). Lady Luck finally shined on me and not only do I have a truck again, but I have TWO of them and both were FREE!!!!!

First is a neighbors old 71 F-100 with a 240ci and a 4 speed. The second, and more importantly to this thread, is my late father’s old 85 F-250 with a 460 and 4-speed that our family friend gave to me.

I had some fuel issues and ended up bypassing the fuel tank selector switch to run only the front tank (switch shorted out and the rear tank has been broken and unused since the early 90’s). That got the truck up and running. Drove it around for about a day with no issues.

Then on Friday, I hopped in and tried to start it and there was a click (sounded maybe like a relay). The click is heard as soon as I turn the key to start and then the truck loses ALL ELECTRICAL POWER to the cab. Power usually comes back once I open/close a door.

I had the battery and starter bench tested and they’re good. My buddy who’s an ASE certified mech told me I should look for a main power or ground that’s loose. I believe I did that. I checked and cleaned the ground from the battery to the block. I couldn’t find the ground from the block to the chassis, but when I reinstalled the starter I replaced one of the bolts with a stud and ran a second ground to the starter from the battery, and another ground from the same stud to the chassis.

Additionally, I used a jumper on the starter relay (to bypass it in case that was the issue) which did the same thing. I replaced the relay and tried everything again, same result.

Can anyone help guide me to what I should check next? Again, there’s power to the cab (dome light is on, buzzer buzzing merrily) but the second I attempt to start the truck I hear a click and lose all electrical power. I appreciate any help you gentlemen can give me. Thank you!

 

Here’s some pictures for your viewing pleasure. They’re not lookers yet, but they will be.

 

Double check your battery connections especially if you have lead battery cable ends. Clean them and the battery posts. Thats the first place to start.

 

Thanks! I’ll can check those again, but those are new and recently replaced as well.

 

Even though they have been replaced, it could be them or the battery itself.

This is like a kink in a garden hose. When you turn the hose off or only use a trickle, you have plenty of pressure. Turn the nozzle on wide open and then you don't have hardly any water and no pressure.

That is what is happening with your truck. The electricity is going through a bad spot enough to run the lights, the radio, etc. They don't take much. But as soon as you need a LOT of current that the starter requires, the bad spot has too much resistance and it knocks the complete system out.

Your electrical system in the cab is getting it's power at the large lug on the solenoid that goes to the battery. So you know the problem is there, or upstream toward the battery. The advice you got about the grounds was a good one, but it could be on the + large wiring also. The current goes around in a complete circle back to the battery.

Get a meter or testlight and put it right on the top of the battery terminals on the battery itself. It should light up or show around 12 volts. While you are holding the meter or testlight on the battery, get someone inside to try and crank the truck. When everything goes out, watch the meter. If the meter goes out, your battery is dead or bad. If it stays at 12v when everything goes dead, then you have a bad connection (kink) somewhere.

 

@Franklin2 thank you sir, I’ll try that out. Maybe I need to scrape off some paint from the new connectors.

 

New terminals on the ends of the battery cables? This style?:



If so, those are nothing but trouble. Either replace the entire cable or get some proper crimp-on terminals installed.

After that, run this test:

https://www.ford-trucks.com/forums/1...w-starter.html

 

x2

The OE battery cables on my 86 F-250 were abysmal. I replaced the entire cables and I didn't have starting issues anymore. Here's a good thread:

https://www.ford-trucks.com/forums/1...-upgrades.html

Here's the stuff I used to fabricate new cables:




If you don't want to hassle with fabricating your own cables here are some good suppliers:

https://www.batterycablesusa.com/

https://www.custombatterycables.com/

Good luck!

 

Threw on some new battery terminals and the old girl started right up! Thank you gentlemen for you’re help!

 

What kind of battery terminals did you install? If you used the bolt-on style pictured above, please don't reply because my brain will explode. But if you did, please keep a good pair of walking shoes in the cab. You will need them when you get stranded. And certainly don't knock over any liquor stores unless you leave the engine running, as those bolt-on terminals are prone to causing problems with hot starts.

 

LoL

If you did use the bolt on terminals Karl pictured above make sure you search for permanent replacements to install at a later time. I can understand the need to get a vehicle back on the road pronto, but you won't be happy with the performance of your battery cables with cheesy terminals like that.

 

I was able to find one that’s an entire unit, cable permanently affixed to the terminal. I’ll admit, I did buy a new, better quality bolt on (not that it makes it acceptable) to use until parts arrive for me to make the new cable w/terminal for the ground side.

As for liquor stores, I work on the side of the law in that regard.

 

I just go to the local parts stores, they have universal black and red cables in various lengths, and usually have 6 gauge and 4 gauge to choose from, and they have ones with the battery cable terminal already made onto it on one end, and a eye on the other, and they also have them with eyes on both ends for going from the solenoid to the starter. Very simple, not very expensive, and they work fine.

 

Been lucky and around here most stores are stocking more and more 2ga in the same styles and lengths. Very few 6ga anymore, except in the bulk "roll-yer-own" bin.
Nothing wrong with 6ga, that a nice 2ga won't cure!

And I should talk... My new-to-me '93 still has the original 6ga cables and works fine. But just looking at them I know I'm living on borrowed time.
Yeah, it's on the list...

Paul

 

Oh, what I actually meant to say ghanson, was congratulations on a successful fix!
Score one for the good guys...

Paul