I have a friend who asked me about a little mishap with her car.
It is a 2005 Taurus SEL, going down the highway the gauges went to 0 (resting state), battery and oil light came on. It wouldn't start back up... after being towed it started up fine...
all of my ideas are ones that I could find a way to disprove them, any help would be awesome.

 

Bad earth? Battery issue? Terminals clean and greased? Ignition switch?

man I`m stabbing in the dark.

 

My first thought was alternator because it happened under power but it wouldn't have started up again without charging the battery... this thing has been bothering me most of the last week

 

I have seen this happen twice in the last 10 or 12 years. From what you're saying is the engine shut off when the gauges went to zero...correct? Car set for a while and cooled down and then restarted...correct?

Both times it was the battery. Check and clean both terminals and check the post coming out of the battery for any signs of being loose, if all these are good then replace the battery.

What happens is the battery has a internal connection problem (an inter-cell connector) the series circuit inside the battery breaks and the alternator can't charge because the circuit is open and the theshold voltage drops and the engine shuts off. The battery cools down and the internal connection refuses and it starts.

Hope this helps, like I said before just ckeck everything really good before you buy any parts.

 

Excellent, thanks!