2004 mustang won't start. The battery seems fine. I removed the cables and cleaned the posts. However, when I try to start, nothing. When I say nothing, I mean the starter is not even turning. However, the battery seems fine because I tried starting with lights on and no dip in lights when i try to start. Seems like the starter relay/solenoid is shot. Funny thing, it was working fine day before, and it just died. It has been cold, around 20 F the last week or so.

Make sure the battery cables are tight on the battery and the starter..

Did you check the battery of the car (maybe loose cable)? but if it just happen suddenly, it might be your altenator that wasn't charging your battery. I think once there's enough power gone through the car then your anti-theft system should work as normal again.

I had the same problem I replaced the battery terminal it worked fine for sometime and it started giving same problem after sometime I cleaned the battery rod and terminal with water mixed with baking soda it works fine. Hope this will help you

If you indeed installed the positive battery cable last and the neg first you blew the computer possible, you will need a complete diagnosis.

A big issue with older cars is battery cable corrosion. Start by checking the battery terminals for white or green fuzzy stuff. That is corrosion. You'll need to remove the cables and clean the ends with a wire brush. You'll also want to look at the copper inside the cable. If it has turned green and has corrosion in it, you'll want to replace the cable. I fixed my sisters Escort with this same issue by following the positive cable to it's first splice and I found corrosion there. I cleaned it all out and the car has been fine since.

this problem could have a few causes.
the battery clamps are corroded and need cleaning
a loose wire from the battery
faulty starter relay
a weak starter

I would start by inspecting and cleaning the battery posts and clamps also make sure that the clamps are fully seated on the posts and tighened securely.
check the battery and starter wires for signs of wear, such as torn or burned insulation or frayed wire, near connectors.
If cleaning the connections in the charging / starting system does no good then you might need to replace the wires completely.

you could also remove the starter (disconnect the battery first!) and take it to a local parts store such as Autozone for testing.

as for the excessive engine revs, this could be something as simple as needing to add some of the proper type of automatic transmission fluid. after you get the vehicle starting again you should check the transmission fluid level

original posted @ http://www.allfordmustangs.com/forums/2005-2010-v6-mustang-tech/120748-2005-2008-mustang-auto-transmission-fluid-adding.html

"Basically, the drain plug on the transmission has another plug in the center of it. You add fluid and use it to determine if the fluid is filled as it is connected to a tube in the drain pan. They tell you to pump Mercon V transmission fluid into this connection. You will need to get a hose adapter to scew into the center tap and connect a hand pump or electric pump to the hose fitting. When you think you have added enough, disconnect the hose, if you are underfilled, nothing will come out, if you are overfilled then fluid will come out until it drains down to the proper level. Make sure the car is parked on level ground when you do this or you will not get proper results. When removing the center plug, make sure you hold back on the drain plug with an open end or box wrench, or you may end up removing the drain plug and will drain the entire transmission fluid that is in the pan, rather than just checking to see if it is full."

I like to start with the free or cheap stuff and work my way up to more expensive solutions.

so in summary
1.) check clean and reinstall battery cable clamps

2.) check wires and connections on starter as well as any power distribution blocks or
engine / chassis ground.

3.) take starter to parts store for testing, take the battery as well, most can test or charge your
battery in as little as an hour.


Finally, if none of these solutions remedy the situation then you may need a new alternator or serpentine belt.

hope this helps

Checked Cables how?

Looking & Touching isn't doing anything

You have to do a voltage drop test or remove
& clean the ends. I would do both

Remove the starter & have it tested at parts store,
assuming you don't know how to do a voltage or
current test while cranking.

Clean your Batterys positive and negative connections both post and cables then charge Battery

If you are trying to jump from the factory "Jump start" terminals and nothing is working, You should suspect your cable to battery connections. Remove the battery cables from the battery and clean the battery posts and the cable terminals. (Auto parts stores sell a very inexpensive tool to do this) Reinstall and tighten the terminals.

Check and clean all connections to & from battery, as in the other ends of cables as well. Make sure starter wires are all in good shape & tight as well. When you hear that click, try to locate area or relay doing the clicking. It may just be a faulty relay. Sometimes it's as simple as removing it and plugging it back in to clean the connection. Do you by chance have a 12volt DC test light to test draw on battery?