I have an 01 ranger 2.3 manual transmission. When you put the key in it might click from a relay once, then nothing. Dash lights dim to pretty much nothing. There’s a rapid clicking under the dash that stops when you hit the brake, turn on lights. If you pull fuse 26 it stops as well. The speedometer will also start rising and rpms do the same. Charged the battery, changed the positive terminal (was corroded very bad) I’m thinking maybe the whole positive cable is corroded or maybe a dead starter.

 

Welcome to the forum

Yes, you are on the right track
Relays and lights need maybe 15amps total key on
Starter motor needs 60-75amps depending on outside temp to turn engine over

The required amps must travel OUT of the battery on the positive cable then BACK TO the battery on the negative cable, if EITHER cable can't pass 60amps then No Crank and lights dim, and relays "click, click, click"
(actually reverse of this but doesn't matter for testing)

So clean and check negative cable as well, yes either of the larger cables could be bad
Could also be starter motor is bad and now drawing over 100amps
Could be battery "cranking amps" are bad, if you have a volt meter test battery when someone turns the key to START, shouldn't drop below 9.8volts


You need to test a car battery AFTER is has been sitting for at least 2 hours after charging
12.8volts is a new battery
12.5v is a 3 year old battery
12.3v is a 5/6 year old battery and time to shop for battery sales
12.2v or lower is a failed battery, get a new one now

 

Thank you. I’m gonna test all this within the weekend. I’m leaning towards a bad positive. When I bought it I grabbed a hold of the cables and pulled on them the + moved. Lost all power while still on the battery post, had to put it in a certain position to crank over. Drove it, parked it, went to take it to the store the next morning dead battery. So that brings me back to the starter draining it. I’ll update when I dig into it.

 

Car Battery's last 5 to 6 years, at 19 years old this vehicle should be at the mid to end of life for 3rd battery

End of life for most can be self draining
Disconnect battery cable, one or both, doesn't matter, test voltage, write it down
Come back in 2 hours and test again, should be EXACTLY the same, any less and its self draining, bad battery