Very Strange Starting Problem

[pb10]

Hello,

My first time posting here so thanks in advance for any help.

I have a 2007 4-door Yaris. Every few times I try to start the car, it will not even turn over. It's just absolutely dead, as if the battery is dead. This has been happening for a few weeks now and I cannot seem to find any trends relating to when it happens or what causes it.

I have found a way to get the car to start though. If I pop the hood and then lift or touch the red cap that covers the positive terminal on the battery, the horn will blast one time and then the car's electrical system will kick in again, allowing me to start the car without any problems. Almost as if I've reset the system somehow.

I really have no idea why the car does this or why when I touch the terminal cap, the horn goes off and the electrical comes back on. If anyone has any ideas, I would really appreciate it.

Thanks!