Expert: Antonio Ibarra Jr. - 4/2/2011

Question
hey like a bone head i was rushing and while hooking up my battery i connected the pos to the neg, just for a second.. but once i turned the battery around i hook it up and the horn sounds, non stop.. i tryed to start it but nothing. i got dome lights but no start.. wont even turn over... could this be a fusible link? and if so witch one? 2007 toyota tundra 5.7 srs... thanks for any help

Answer
Hello Dan,

It sounds to me like there are a few different things going on here.  Lets break them down one at a time and get to the bottom of the problem.

First, NEVER rush a battery install, doing so can not only cause problems like the ones you currently are experiencing, but it can result in serious injury or death to you, if it is not done properly and the battery explodes or POPS.

As for the horn sounding, it sounds to me like you may have blown the horn relay, and it is now stuck in the OPEN position, causing the relay to supply power to the horn wires when the horn isn't being pressed.  Check the horn relay and horn ring circuit for proper function and replace as needed.

As for the non start issue, it could be one of a few things:

1. You may have blown a fuse or MAIN fuse or MASTER FUSE in the electrical system.  Check all fuses in all fuse boxes for proper function and replace any that are bad.  If it is a MASTER FUSE, it will be located in a wire coming from the battery or alternator the wire will have a black box in the middle of it somewhere.   Inside that box is a MASTER FUSE usually 125 Amps or more, if this blows the car will not start.  Check for the master fuses and replace as needed.
2. You may have blown your starter solenoid, check the solenoid for proper function, if the solenoid is blow the starter will not work, and the engine wont crank or start (Turn over).
3. You may have blown a fusible link.  If this is the case it will be connected to the battery and/or alternator.  They will be THICK GAUGE wires, usually red or a combination red and some other color.  To check them tug on them gently but with some force, if there is play in them or they feel loose or wiggly, replace them as they are blown, however if they are hard or have no play they are good.

I would start with the above options.  Please keep me informed of your progress and how you make out.  If the above does not rectify the problem, please let me know and we can go further into the diagnostic process.

Thank you, Good Luck