Hi
I have a 1994 F250. I haven't driven in a month or so, maybe longer. I went to start it the other day and the battery was completely dead. (Battery is only about a year old) I put it on the trickle charger and it took a day and a half to recharge. When I tried to put the battery in today. it sparked really bad as I tried to put the cables on. The neg cable slid and touched the neg post and the solenoid on the right firewall started smoking really bad until I got the terminal off the battery.

Can anyone direct me where to start looking for the problem? It had had an issue with a slow drain on the battery, but has never completely drained the battery like this.

Thanks in advance for any help!

Scott

 

Bummer! you will have to search for the short, don't install the battery, or have the key switch on, you'll fry the computer. Start with the pos + cable to the starter, clean up connections + & - get a multimeter and check the solenoid, and starter for resistance, and look for what it is that may have lost its jacket and is grounding.

 

Are you sure you didnt hook the battery up backwards?

 

Ford says if you are going to not drive for Two weeks unhook the battery. So it is normal for a battery to be down after a "month or so, maybe longer".

Smoking around the Starter relay when a battery is hooked up sounds like you are cooking the fuse links. Look at the AC Generator wiring form from the Starter relay to the AC Generator.

You can also try hooking up the trickle charger without the battery in the truck for testing. If you have a short the circuit breaker in the charger will trip.

 

What you can do to isolate your fault is to install the battery but place a 12V bulb into the circuit (use some test clips). This will limit your current to whatever the bulb draws so you don't damage anything else in the vehicle. Then start pulling fuses and power wires until the light bulb goes off, and narrow it down from there.

 

You didn't charge the battery backwards did you? I've seen people do that before

 

My dad did that with a battery that ran an electric fence, asked me what he should do... I said hook it up backwards and when it goes dead recharge it normally. I'm not sure if the battery survived or not but I'd never seen or heard of that before then. I put the voltmeter on it and it read negative 12 volts!

 

Yep, that's what I did. Charged it backwards! The cables won't reach to hook it up and discharge it so someone else suggested I hook a headlight up and let it discharge and then recharge. Do you think I burned anything up in the few seconds it was hooked up?

Thanks for all the help!

Scott

 

Hopefully just a fusible link burnt. They are attached to the starter solenoid. when they burn sometimes they look ok but if you pull on them and they stretch the wire inside is burnt in two.

 

It's possable the fuseable links got fried. Tug on the wires by the solinoid, and if they strech, or seperate, they're fried. Don't replace them with fuses, they won't work properly, go to the jy, and get some. You can also buy resistor wire,to make the repair, but I don't know what size you will need, someone here will know what size

 

Besides needing a new battery, you also will have to see if anything else in your electrical system got damaged. Reverse polarity can cook the rectifier diodes in your alternator, and this will cause a permanent (ie key-off) battery draw of a few amps or more.

I'd still do my suggestion above when you install your new battery (with the light bulb in the circuit) just to see if there is anything still shorted out. Don't try to use your existing battery, it is toast if it has had complete polarity reversal.