Bad battery or terminal cable?

I've got a 2013 TRD Sport with just under 30k miles.

Three times in the past two months, my truck has randomly not started. Today, for example, I left for work and stopped at the 7-11 on the way. When I went to leave 7-11 the truck wouldn't start. It doesn't make any sounds and none of the dash lights come on (doesn't try to turn over or anything). I've figured out that when it happens if I pop the hood and play with the positive terminal cable it will start right back up. My scan gauge is reading the battery at 13.6-13.9 volts depending on if I have my lights turned on and phone charging or not. As far as I know that's a normal charge for a battery.

Does this sound like a problem with the terminal cable or the battery to you all? I'm leaning towards the cable but wanted some input from you all. I'll be having Toyota fix it (calling to set up an appointment on Monday) but would like to know better what is going on before hand. This is the second engine in the truck but I don't know if that makes any difference or not. Thoughts anyone?

 

Sounds terminal to me. You can read 13V all day long, but a bad connection will not allow CURRENT to flow.

 

Yea that was my thought process. It's acting the same as if there wasn't a battery in it at all, I just didn't know if there was any chance if the battery itself intermittently losing connection to the post or something.

Do you happen to know if it is something that would take a while/be challenging for Toyota to fix?

 

Have you taken the basic steps of cleaning the terminals and connectors then tightening them back up?

 

Yup, both posts and terminals are clean and as tight as I can get them. All I can think of is the wire is bad.

 

Wire itself doesn't typically go bad without some help from the user ( smashed or cut etc ...). You may well have a loose wire somewhere.

Can you move either of the terminals on the post without loosening it? If your answer is yes, it isn't tight enough.

 

If you have a voltmeter, check where you are losing the voltage in both the positive a negative (ground) cables and terminals. Depending on the temperature, a weak/partially charged battery, bad ground connection, starter solenoid contacts or worn brushes can exhibit the same symptoms. Occasionally the battery's terminal will have a bad cable crimp or internal corrosion causing the voltage drop from a high resistance connection. You also could have a unhealthy charging system, battery or starter. Most auto parts or battery stores will test these for no charge.

 

In OP, if it acts like there's no battery at all, it's very possible one of the posts is broken inside the battery case. When you fiddle with it, contact comes back and it manages to reconnect itself for awhile, then fails again.
It should be under 3/36k warranty; dealer should replace the battery.