electrician90

So I have a 99 F150 4.2 that has not been started in about a year. I went out to try in start it surprisingly the battery was not completely dead but it did not have the power to start the truck it would crank maybe a half a turn then stop. So I bought a jump pack hook it to the battery and it cranked a lot faster but for no reason everything quit working. No light no crank no start no anything not even the fuel pump would make noise. I went online to research but can not find any videos or anything to help me out. Please Help I need to get it fix so I can work on my wife car before it breaks down PLEASE PLEASE HELP

BareBonesXL

Sounds like a dirty/corroded battery cable terminal. Clean the post and the terminal and if you have the clamp-on cable terminals, clean the copper under the clamps.

Pretty common that when more current is pulled the dirty terminals open up from the heat.

Could also be that you tripped a breaker in the jump-pack. Maybe too much juice was pulled by the bad battery. Check the breaker.

electrician90

The terminals and cable ends are clean the jump pack works fine. I have no power from the battery to the truck no lights no fuel pump making noise. What next

sally2001

You need a new battery. If it has been sitting a year it probably has a dead cell and won't supply enough power to start even with a jump box.

Clench Beastwood

Not really, the jump pack should put enough through the cables as it's most likely clamped onto the cable ends on top of the battery terminals, to at least get a door dinger or dash lights. If it's getting nothing with the jumper on, and the jumper is operating correctly, it's most likely a disconnect somewhere in the wiring, perhaps a ground strap broke or one of the cables broke inside the sheathing somewhere. I would start following the cables, tracing grounds, etc.

akdoggie

Something else to think about. In a 99, you probably took out the fusible link in the harness. 97-98 has 175 amp Megafuses, but the 99 up should have an internal fusible link in the starter cable side harness. You could have also burned out the solenoid on the firewall so it doesn't allow power to flow thru. If that happened, you can get a fusible link at O'Reilly's or AZ for under 10 bucks and solder it in, tape it up, and be good.

Just a couple thoughts for you to look at, besides the bad cable connections or faulty battery. Good luck.

ProjectSHO89

Hmmm. has the word "electrician" in his screen name but doesn't know how to diagnose a simple open power or ground feed? Oh, the irony!

Nope. That would only prevent the starter motor from engaging. He reported a completely dead vehicle which means a fault in the primary power circuit (battery, battery cables, connections, or mega-fuses for the 97-98)).

I'm going with a connection or cable problem as the most likely based on the limited info provided.

Clench Beastwood

Agreed, I would test the battery, or get it tested. Then charge it up, or get it charged. And put it back in the vehicle. Then begin testing from the battery out, using a multimeter or test light. You can youtube how to use a multimeter if you don't know, I'm not writing a novel 😉
Looked up some videos for you.

This guy is generally pretty spot on.
dial2fast - YouTube

3 Videos for testing automotive wiring.
VIDEO 3 – Test Car’s Ground

ProjectSHO89

An "electrician" would know to first get the multimeter out first to see if the battery even needs to come out or be charged.

BareBonesXL

You can also test continuity and resistance through the positive cable to negative cable circuit, with the battery disconnected. Open a door or turn on a light switch to be sure there's a path. That will determine if there's a break in the main circuit.