I need some help! My mustang keeps not starting. It is not the battery, the starter, spark plugs, ground or positive battery wires, or fuel. Basically when you open the door the dome lights come on and when you put the key and turn it the dash lights come on but as soon as you turn it to crank it over and start it everything goes out, air, lights, dash lights, everything. It did this to me a month ago with my brother in a parking garage and we just kept messing with wires until just when we were about to give up it started and I was able to drive it home. I have started it several times since then but today it did it again. The difference today was that after it shut down the alarm light flashed for about ten seconds. Once it goes out there seems to be no recovery of function. I am thinking wiring issues or maybe the chip in the key. Any ideas!?

 

Check the battery with a volt meter. it should read around 13 volts if it any good. What do the battery terminals look like?

 

The battery is brand new and is showing 13 volts. the terminals are clean and have good contact. when I get in the car the theft light is flashing on the dash.

 

Sounds like a bad connection somewhere.