Car won't start but battery is fine and starter is fine

Worn solenoid contacts is a very common cause of failure to crank with the little silver Nippendenso starters but you'll hear a single rather loud clunk each time you turn the ignition switch to "crank". The contacts can be replaced for 20 bucks but most people just replace the entire starter. The problem always starts out being intermittent and will take more and more turns of the ignition switch before it cranks as the contacts wear away. The problem will get progressively worse over the next weeks and months.

Here is a guide to help.

https://www.2carpros.com/articles/car-cranks-but-wont-start

The cracked cam on the end of the tumbler is somewhat common too. The dealer has a repair kit for that.

Yep ever though it tests good it can still be bad because under load is a different bag of worms. Here is the starter at Amazon for $54.00

https://www.amazon.com/gp/product/B007Y85SDK/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B007Y85SDK&linkId=341b0df99e2bb4c99fe908811077c9f6

Here is a guide to help you out as well.

https://www.2carpros.com/articles/how-to-replace-a-starter-motor

you will need to jack the car up

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

These kits are available now from most farm supply / hardware-type stores and will come with four contacts and a plunger. You might find two different kits available but either one will get your starter working. All starters use the same "battery" contact. That is the smaller one and goes under the bolt that the fat starter cable from the battery bolts to. Of the other three contacts, you'll see one is symmetrical, and the other two are offset, one one way and the other one the other way. I have never found a way to figure out which one of those three "motor" contacts you need other than by looking. Just use the one like the one you take out. You'll have two contacts left over that aren't used.

These kits come with the plunger too with the copper contact disc built in. In most cases that disc is not burned away so the plunger doesn't have to be replaced. There are three versions of that plunger. The only difference is the length of the spring-loaded push rod. One is about 1/8" longer than the other one. Here again, I don't know of any way to tell which one you need other than by looking. The parts books might list different kits for different years, but all of the Chrysler starters interchange so there's no guarantee the starter on your car now is the original one or from the same year.

There is a third plunger with a much longer shaft that is used only on Toyotas. The last time I checked, that one is not available from the rebuilders. You have to buy that one from the dealer, although the contacts are the same as those on the Chrysler starters.

Be sure the contacts sit flat as you tighten the nuts. That insures they make full electrical contact with the plunger's contact disc. You'll see the step on the old contacts where the copper burned away when you compare them to the new ones. In rare cases the plunger can get wedged between those steps and refuse to disengage. That happened to me once. Had to remove the battery cable to get it to stop cranking, then had to unbolt the cover and pry the plunger back with a screwdriver. I put that starter on my '88 Grand Caravan in place of the original Bosch starter. The Nippendenso bolts right on with two instead of three bolts and works just as well.

Other than those contacts, the motor and gear reduction assembly give extremely little trouble, so there's no need to have to replace the entire starter. Most people DO replace the whole unit because they don't know about the contacts or how inexpensive they are to replace.

Don't be too hard on your mechanic. The cracked cam on the ignition switch tumbler and the solenoid contacts are two totally different problems that are both fairly common, so when he fixed one problem, there would be no reason to expect to find the other one at the same time. You've noticed they have different symptoms too. With the cracked cam, the switch doesn't turn quite far enough to hit the "crank" position so there's no sounds. Just the dash lights turn on like normal. With the solenoid contacts, the starter makes a single loud clunk when it engages but then it doesn't switch the starter motor on.

If you run into problems or have questions, holler back, otherwise we want to hear when it's fixed.

You're likely hearing the starter relay. The ignition switch can only handle about an amp of current. It turns the relay on which switches about 20 amps to turn on the starter solenoid. Along with pushing the starter's drive gear into mesh with the ring gear, it turns on the 125 to 150 amps it takes to run the starter motor. So there's three circuits; the low-current ignition switch / relay coil, the medium-current relay contacts / solenoid, and the high-current solenoid contacts / starter motor.

There are other relays that will click when you turn on the ignition switch. Most notably, the automatic shutdown, (ASD) relay will click on for one second, then again during engine rotation, (cranking or running). Most cars have a separate fuel pump relay that turns on and off at the same time. You can usually tell if the starter relay is clicking by putting your finger on it to feel the click when a helper turns the ignition switch. If it's clicking, the contacts might be pitted or arced and not sending current to the starter. Swap that relay with a different one like it to see if that helps. If the relay doesn't click, that cracked cam on the ignition switch cylinder would be the more likely suspect, but there could also be a bad neutral safety switch. Usually a bad switch will cause it to not crank in "park" OR "neutral", but if it does crank in neutral, you can be pretty sure it's a bad switch or, on some other brands, it's out-of-adjustment.

Lets pursue this before you tear into the starter. When it won't crank with the key, remove the starter relay from its socket, then grab a piece of wire or a stretched-out paper clip and connect the two terminals shown on the right or terminals 30 and 87 if you have the square relay like on the left. Be sure it's in park, or the ignition switch is turned off so the engine won't start. If the starter cranks normally, you've just bypassed the ignition switch and the neutral safety switch, and you've proven the starter and both fatter battery cables are okay. If it still doesn't crank, we'll need a test light or digital voltmeter to figure out the problem.

Some cars where built with a safety switch on the brake pedal, it was a short run but they are out there. If it cranks exactly when the brake lights turn on, that would suggest something electrical is involved. If it cranks before or well after the brake lights turn on, then I'd be looking for something flexing and making intermittent contact. A couple of things come to mind. We had a '97 Dakota that Chrysler donated to our community college. It had an automatic transmission but to eliminate the need to design and build a totally different wiring harness for trucks with manual transmissions, they installed a jumper wire under the dash where it would have a clutch switch. For safety, you had to push the clutch pedal down to crank the engine. Since there's no clutch pedal with an automatic, they put that jumper in there in place of the switch. I built a lot of "bugs" that I could switch in and out for my students to practice diagnosing, and one of them was a stretched-out pin in that connector. Sometimes it would still work properly if you wiggled it a little. You might want to look under your dash to see if they use that same jumper on your car. In the Dakota, it was a dark green connector with two pins and a 4" yellow wire connected to those pins. On the assembly line someone plugged that connector into the clutch switch or that jumper, but since you don't have to worry about that, the connector and jumper can be cut off and thrown away, and the two wires can just be soldered together.

The next thing to look at is the electrical connector on the ignition switch. There was a lot of trouble with the contacts overheating in the switch, and that heat would migrate out to the connector where the terminals would get black from overheating and the plastic body would start to melt. There's multiple circuits in the switch and the one affected was almost always the heater fan / power window / radio / turn signal circuit, but if it is loose, I could see it flexing a little when you press the brake pedal and possibly affecting other circuits. Some electrical tests with a test light will help identify that before you tear the steering column covers apart. With the starter relay removed and your test light's clip lead grounded, you should find 12 volts on terminal 85 or 86 only when you turn the ignition switch to "crank". Sorry I can't remember which one. If you do, that entire circuit is working. If you don't see 12 volts, we have to work backward to find where it's being lost. Next, if you do find 12 volts on one of those two terminals, move the test light's ground clip to the battery POSITIVE post, then probe the other terminal, 85 or 86. The test light will light up if there's a complete (good) path to ground, and that is going through the neutral safety switch. If you do have a lit test light, it will go out when you shift to reverse or drive. It should only be lit up in park or neutral. If both of those circuits are working properly, the relay should be clicking when you turn the ignition switch.

A totally different way to test the circuit is to pop the cover off the relay and stick it back into the socket that way. Now you can watch the little flipper while a helper turns the ignition switch to "crank". If it trips, you know the entire low-current circuit is working. That includes the ignition switch, neutral safety switch, coil half of the relay, and all the wiring between them. If the flipper doesn't click, one of those two circuits isn't working.

Next, you can squeeze that flipper yourself. That will energize the medium-current circuit and send current to the starter solenoid. If the starter cranks, you know the relay contacts, solenoid coil, and wiring between them are good. Plus, since the solenoid energized the starter, you'll also know the entire high-current circuit including the battery cables and solenoid contacts are okay.

Okay, first you have to determine if it's really the starter relay that's clicking because other relays will be turning on and off at the same time. If the starter relay really is clicking, there has to be voltage on 85 or 86 when you turn the ignition switch. That means there's something wrong with your test light setup. That happens to us all the time. Touch the probe to the battery positive terminal. If it lights up, that at least proves the ground clip connection is okay. You can also probe 30 and 87. One of those two will have 12 volts all the time.

If you pop the cover off the starter relay, look closely, and physically see the flipper moving, we'll know that entire circuit is working. If it's not moving, we'll have to get more in-depth with terminals 85 and 86.