I have a 1986 Ford ranger that when I go to turn key sometimes it will try to crank but then sometimes i go to start it and it won't do anything. occasionally i could wiggle my battery cables and it will help. Before i would hear a loud thunk, but now I cannot get it to do anything at all. I have worked tirelessly to try to fix my truck but i have had no luck at all. Im thinking that maybe i have a bad ground issue but I'm not sure what's going on please help!!!

 

Welcome to the forum

You shouldn't be able to "wiggle battery cables" they need to be clean and TIGHT
Clean battery terminals and the inside of battery cables, then tighten them up

Follow each of those cables and clean those ends and surfaces they connect to, and retighten
If cables seem brittle or you see corrosion, replace the cables

 

I guess i should've been a little more clearer i wiggled the wire but everything on the terminals is clean and tight. Now when i get it and try to crank it out just makes a loud thunk and ty nice to meet you

 

I have also bought new cables and a brand new starter relay

 

Then new starter may be the issue, "THUNK" noise sounds like starter is not working like it should

"New" starters, and alternators, often fail in a first few months, just a heads up

 

Ty so much i will look into that right away ty so much for the help

 

Well i did have a starter issue, but now upon putting another starter on, now i have nothing again it's like my battery is completely dead. But i had it tested to, i have continuity in my neg cable at the solenoid but not at the positive, is that correct? I am so lost!!! Okay this morning i get in the truck i turn the key to the run position and when I do,i see a very quite and rather like spark come right from the negative terminal. What do i have wrong!!! Please help there is also a case ground wire that has no insulation at all on it. It's an aluminum wire that comes from the computer inside the cab at the passengers foot. This wire connects or runs with another dark blue and black wire then I'm assuming is another ground but when it goes through the firewall into the engine compartment it is wrapped in some kind of aluminum sheeting with that other wire it has come loose from somewhere at the the other end of the wiring harness or dr wherever it is I have no idea where it goes is there anyway that you could help with that too please

 

1986 has a Starter Relay(often called solenoid) on the inner fender near the battery
It has 2 larger posts and 1 or 2 smaller posts

Can look like this: https://i5.walmartimages.com/asr/5a4...0&odnBg=ffffff
Or this: https://i.ebayimg.com/images/g/IZUAA...kNK/s-l500.jpg

The smaller posts are labelled "S" and "I"
Only the "S" post is used after 1980 or so
Which is why newer ones only have the one "S" post

Should be a red/blue stripe wire on the "S" post, that comes from the ignition switch in the cab, this wire only has 12volts when key is turned to START and that activates this Relay

One larger post should just have one wire/cable on it, JUST ONE, it runs to Starter Motor's larger post
Either larger Relay post can have this ONE CABLE, the just 1 cable is important

The other larger post on the Relay will have the Battery Positive cable on it, this is the 12volt distribution for the whole vehicle
On this larger post will be several other wires with the battery positive cable, these power fuse boxes lights, everything
Alternator is also connected here, to change battery

There are no Battery Negative wires on this relay, the relay IS grounded by the two screws that hold it on the metal inner fender, so it must be bolted down to work


Battery Negatives(ground) larger cable should run to a starter motor bolt, that holds it to bell housing, or it runs to the engine's block
This is to ground the starter motor and Alternator
There maybe smaller Battery Negative wires that run to inner fender metal and Rad support metal, these ground the relays on inner fender and the head lights

There is also a Ground strap on rear of drivers side head that runs to Firewall this grounds the Cab electrics