Tacoma Won't Start

Truck won't start. My battery is new. I played with the terminals and I got the lights to turn on inside but then when I try to turn the key to turn it on the entire truck electrical shuts off, no lights at all or horn. I tried tightening down the terminals and it gets my lights on but only to turn off when I try to turn it on. I need help ASAP pleasee

 

Have your battery tested just in case. Check your fuses. Make sure the battery cables aren't corroded or frayed.

 

all the cables look a little old but it's never stopped the truck before. My battery is also not mounted down, meaning as I drive it slips around and I think the initial problem was that the terminals got loose.

 

Since you get lights with messin with the terminals i too would guess a section of your battery cable is corroded inside the insulation where ya cant see it. Could be a battery problem but since you get some action with tinkerin with the cables id start with them...batt test is usually free though, so worth a shot if its convenient at all...