2007 Mercury Mountaineer trouble starting

The car is having problems starting. With the key in the ignition, it will turn on the electronics and lights, but the car will not start. An hour later, it may start with no problem. I took the car to a local Ford dealership to get checked out, and was assigned a service technician who stated that he had owned three Mountaineers. After performing a diagnostics check, he concluded that the computer system was not recognizing the keys and I would need to get new keys made. After paying over $500 for new keys, the problem was not solved and the service technician hasn’t figured out the source of the problem. I’m getting ready to sell the car, but would like to fix the problem first. Has anyone experienced this problem? If so, what advice can you give?

Please explain in more detail what happens when you try to start the car. Does the engine crank ok? That rr rrr rr sound? But not catch and start? Or does it not even crank? If so, what does it do besides not cranking?

Battery connections are the first place to begin when you have a “No Crank” situation. Even
if you have a new battery, if the connections are loose, dirty or corroded, you will not be
allowing the full flow of current to pass thru the connections. The connection may be
enough to turn on the lights, but not enough for the huge flow that is needed to operate the
starter. This is where many people say that they know the battery is good….”because the
lights come on”. This is no more a battery test than licking a 9volt battery. It only tells you that there is electricity…not how many volts or the amperage that flows from the battery.
Jump starting may have wiggled the terminal just enough to allow the current to pass and start the engine, but tomorrow you have the same problem.

First remove the cables from the battery and use a wire brush to remove any corrosion and dirt from the battery posts and the cable terminals. There is a tool with a round wire brush for this purpose, found at any auto parts store for less than $10 http://shop.advanceautoparts.com/p/kd-tools-terminal-battery-brush-kdt201/25980576-P?searchTerm=terminal+brush.
Before connecting the cables, apply a coating of di-electric grease to the battery posts this will keep oxygen away from the connection so that it will not corrode as fast.

It is just as important that the other end of the cables also have a clean connection. Remove the negayive cable from the battery again so that you do not short anything out. Follow both cables to their far ends, remove this connection and wire brush the connection and the cable terminal clean and retighten these connections.

If there was work done recently, there may have been an “engine to body” ground that was not installed following the work. These grounds normally run from the rear of the engine to the firewall and are uninsulated and most are a braided wire. If any of these are found unattached…reattach them.
Remember….this is not a “Sherman Tank” don’t over tighten the connections.
Tight…tight………………too tight…broke!!!

Yosemite

Thank you for the information. We will discuss this with the service technician and let you know if it turns out to be anything other than the battery connections.

The next time the engine won’t start, with the dash lights on, step on the brake pedal and shift the transmission into neutral and then try starting the engine.

If the engine starts, it points to a problem with the transmission range switch.

Tester