I left the keys in the ignition last night. I didn’t think it was left on, but apparently it was. This morning when I tried to crank the truck, it wouldn’t start. The dash lights came on, but it didn’t make any sound. I tried to jump it off, and it still won’t turn over. Any suggestions as to what it could be??
Additionally, the truck that wouldn’t start was a 97 Ford F150, the car I was trying to jump it with was a 96 Honda Civic. Someone told me that might be the problem, that the small car wouldn’t give enough power to a truck…
The small car wouldn’t give enough power to a truck— You should avoid whoever made that idiot statement–Have the battery properly charged as a first step.
I’ve started cars using my motorcycle before, so ignore that person, whomever it was.
Did the dash lights dim when you turned the key?
Possibly… I am at work right now so I can’t try it right now. If they dim or don’t what does that mean? I’m so sorry I know nothing! I tried to find an answer online on my lunch and was unsuccessful!
If the lights on the dash dim that means the battery charge is to low to supply power to the starter. You can purchase a battery charger from Wal-Mart for less than 30.00, that is cheaper that a service call and less risky than jumping from another vehicle if you don’t know what you are doing.
Ok, cool. Thank you!!! 
You probably didn’t allow the donor vehicle to be connected to the dead battery long enough for it to recharge the battery.
Connect the jumper cables, start the donor vehicle, and bring the idle speed of the donor vehicle to 2,000 RPM’s for five minutes.
That’s usually long enough to recharge a discharged battery so the vehicle will start.
Tester
Do I have to leave the key of the dead vehicle in the ignition or in a half way start position or leave the key out of the ignition completely?
Don’t even put the key in the ignition of the dead vehicle until you go to start it after allowing the battery to be recharged.
Tester
+1 to Tester. Keep the keys in your pocket until 5 + minutes have passed
OK I am retracting my previous advice. From the OP’s questions the only sane thing to do is pay for a road service call and have someone who knows what they are doing get the vehicle started.
I wouldn’t attempt to jump start this truck. When the battery is severely run down like that, jump starting could damage the electrical system of either or both the truck and the other car giving you a “jump”. And you always run the risk of battery explosion. Why take the risk?
What I’d do in this situation, after making sure the key is out of the ignition and everything is powered off, I’d remove the battery, put in on the floor in the garage, and charge it using a battery charger. On the low setting, which is usually a 2 amp rate. For 12-24 hours. Follow up with a good cleaning of the battery posts and connectors. You should be good to go.
If your truck doesn’t like having the battery removed b/c it confuses the computer, let us know. There are ways to keep the computer powered up and still remove the battery for most vehicles.
If OP isn’t familiar with shop procedures associated with battery removal and re-installation, suggest to not learn by doing. Let a pro do it, or at least have someone knowledgeable show you how the first time.
The Civic CAN and Will easily be able to start any other 12VDC vehicle… My guess is that either the cables were worthless…and or were not adequately secured to each vehicle… This happens an awful lot of times… Many times i see jumper cables that are totally worthless.
If you can find a battery charger then use it… Otherwise use a different set of jumper cables OR be very sure that they are very securely connected to each vehicle.
Another issue can be that the run down battery just wont take a charge any more…batterys “Die” in this manner all of the time. Their internal cells wont take a charge anymore when they get old and especially when they suddenly get run down to very low voltages.
Blackbird
These http://www.harborfreight.com/12-ft-10-gauge-heavy-duty-booster-cables-69294.html
are useless. The wire simply can’t carry enough amperage. If this is what you have - even if new - just toss them in the recycle bin and get a good set.
yes, 10 AWG is too thin. Voltage drop over 24 feet at 150 amps is:
resistance is 1.6mΩ/ft, (aluminum) so voltage drop is 5.8 volts. Add in the drop in the clamps and connections, and you are probably well over 6 volts. Which means the starter only has 5 volts to work with, not enough.
Harbor Fake . . .
I jumped my neighbors V-8 car off my lawn tractor battery.
The only way 10 gauge jumpers can be used is to hook them up and let the idling car charge the dead battery for 10 to 20 minutes or so and then try a start.