Car won't start -- but only sometimes

First thing you should do is clean your main battery ground connections. Your neutral safety switch theory isn't likely because it doesn't fit with your initial statement: "I turn the key, and I hear a click, and the radio and lights turn off"

-jim

I think the taurus has the solenoid on the starter, at least the pictures look that way. Your starter will have two electrical connections, the big one should be hot all the time and that one actually powers the starter motor. Check it for battery voltage. The 'click' you are hearing is probably the starter solenoid. It will have the smaller wire hooked to it, and the other end of that wire is connected to the ignition switch. The neutral safety switch you refer to is between the ignition switch and the solenoid.

Want to rule the neutral safety switch out? Put the key in, turn it to run, and put the car in D. Now turn the key all the way to start. You shouldn't hear the click. Put it in neutral, you'll either hear the click or it should start. Same in Park, it should either click, or depending on your luck, it will turn over and start. All other positions, you should not hear the solenoid click.

If that test goes okay then you should still test the starter solenoid by itself. Start by testing for battery voltage at the solenoid connection while you have a helper turn the key all the way to the start position. With the load of the solenoid in place the battery voltage will drop, but you should see the same voltage at the battery and at the solenoid terminal. Any loss of voltage here would tend to implicate the wiring between the battery, ignition switch, neutral start switch, any alarm you might have, and the starter. If you have your helper hold the key in the start position when it isn't cranking you can use your voltmeter to measure across the battery terminals, and then between the negative terminal and the solenoid terminal. Both readings should be very close to one another.

Another way to check it is to use a jump wire to manually connect the solenoid connection to the positive terminal on the battery. If you put the key in, turn it to the run position, and then jump the solenoid connection, the engine should turn over and start. If you get the click no-start treatment going this way, I would check the big connection at the starter and both of the battery cables at the battery, make sure both are clean and tight. If both of those are good I'd pull the starter, as it is probably worn out.

Given the fact that you're at 130k you're probably about due for a starter anyway, and if I had to make a guess as to what is wrong without seeing the car based on what you are describing, I would suspect the starter is probably what is at fault.

Good luck with it.

Chris

As some else pointed out it is easy enough for you to to test whether it behaves the same in park or drive. If it all acts exactly the same when you turn the key to start in drive then it may be a faulty neutral safety switch. If putting it in drive and turning the key to start gives you something different then I would start with cleaning the battery terminals and grounds.

-jim

-jim

i think there is a brake pedal switch maybe involved in there somehow as well,,,

I had a Taurus that would not start due to a bad brake light switch...

Mark

|> Lately, it occasionally refuses to start. ?I turn the key, and I hear |> a click, and the radio and lights turn off, and it doesn't turn over. ...

| Given the fact that you're at 130k you're probably about due for a | starter anyway, and if I had to make a guess as to what is wrong | without seeing the car based on what you are describing, I would | suspect the starter is probably what is at fault.

I suspect you may be right.

The problem hasn't happened enough to really troubleshoot, but the last time it happened mucking with the transmission control didn't have an effect -- but banging on the steering wheel did. Or maybe it was just a coincidence?

I'm now thinking there's a dead spot on the starter, or something like that -- but any sort of vibration of the car can get it past that. So I just need the problem to happen more reliably so I can troubleshoot it and fix it.

Thanks guys.

There was a problem with those ignition switches, a recall IIRC. Time to get out the volt meter and see if you are getting battery voltage to the solenoid with the ignition switch in the crank position.

HTH, Ben

If banging on the steering wheel helps, you're probably looking at a bad ignition switch.

| If banging on the steering wheel helps, you're probably looking at a bad | ignition switch.

Well, if so, there must be multiple switches in the ignition engaged when you turn the key from `ON' to `Start', with some working and some not, because I do hear clicking in the dash (not the engine compartment) and the radio turns off (because it always turns off as I start the car -- it's not because of a weak battery. It doesn't `brown out' -- it explicitly turns off.)

Either way, it's not happening often enough to really diagnose. Which I guess is OK, as long as it doesn't decide to strand me somewhere :) (But I am carrying the needed tools with me, and really, if the problem is merely a switch as it seems to be, I'll be able to hotwire it to get myself home easily enough.)

You can remove the starter motor and take it to an auto parts store and let them check it out.Or take it to an auto electric repair shop.The old starter motor could be dragging. cuhulin