Wednesday, June 22, 2011

Car will not crank?

Troubleshooting tips for a car/truck that does not crank:
Some people confuse the terms "crank" and "turn over" as being different, but we use them interchangeably. If your engine turns fast enough to start the car but the car doesn't start, then please click this link and refer the troubleshooting procedure:---

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To turn over, the car needs battery power or a jump from a good battery or high-power charger. Do not assume you have a bad battery just because it will not crank the engine.
Troubleshooting steps depend on the exact symptom you are experiencing. If the starter solenoid is clicking, your start circuit is likely to be good and the troubleshooting will be more limited. We will first consider this easier case and then the case of no sound at all.

PLEASE READ THIS: When jumping a car, always keep the other car running and make sure you have a rock solid connection to the correct terminals. A buzzing or click-click-click... is almost always caused by a low battery or bad jumper connection.

Solenoid clicks but starter does not crank: run these tests:
1. Try to jump start at battery terminals.
2. Unhook the jumpers and jump the solenoid as follows. With the car in park or neutral and the parking brake on, short the hot terminal (one with the big red wire attached) of the starter solenoid to the smaller (ignition switch) terminal. Be careful not to let your screwdriver touch anything else, especially do not touch the big ground terminal closest to the starter motor. Here is a picture to guide you:



3. Only if tests 1 and 2 above fail to crank the engine, smack the starter motor (not the solenoid) with a hammer, then try to start.

Solution options for solenoid clicks case: Based on results of above tests, here are solution options:

If smacking the starter is the only test that worked, you have a dead spot on the starter commutator--replace the starter.

If it will jump start but will not crank by jumping the solenoid, check to make sure the battery terminals are clean and tight.

If it will not jump start and will not crank even by jumping the solenoid, the problem is either the cable to the starter or the starter/solenoid itself.
check the big red wire that goes from the battery to the starter and make sure it is strong and tight at both ends. If that is good, replace the starter/solenoid.

If it will not jump start but will crank when the solenoid is jumped, the problem is with the start circuit not getting sufficient current to the solenoid. This usually only happens when there is a separate starter relay (in the engine compartment relay box) that is worn out. Replace the starter relay
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Solenoid Does Not Click-no sound: If there is no sound when you try to start the car, run the following tests:
1. Try to jump start the car. If the car jump starts, your problem is power. Make sure the battery terminals are clean and tight, and if this isn't the problem check the battery and alternator. Try charging the battery.If the battery will not charge, replace the battery. If the battery will charge, go to dead battery troubleshooting ,click this link:---


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No Jump:
If the car will not jump-start, first also verify that the red cable from the battery to the starter is strong. If this cable is solid and connected firmly, either your starter/solenoid is bad or your start circuitry is bad.There are various starter/solenoid designs here, but in most cases the solenoid serves both to engage the starter gear to the engine flexplate/flywheel and to close the relay putting power to the starter itself (some designs have the solenoid separate from the starter and the starter has it's own mechanism to engage the flexplate). When the battery is low, you can usually hear the solenoid click but the starter will not get enough power to crank the engine.
Going forward from here, I'm assuming your battery is well charged or you are jumping from a well charged battery.
Circuitry:
Typical starting circuit.


Not all systems have the extra starter relay or body control module components. There may be an additional "start" fuse or relay in the engine compartment relay box. The fuse may be before or after the ignition switch in the circuit. In the above diagram, the ignition switch and fuse are before the top of the diagram. Check any fuse marked "start" first. If there is a relay, you can click this link below and follow the procedure:---
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In these designs, the command signal from the ignition switch may be negative or positive. If you aren't sure, see if you can get the wiring diagram for the circuit. If the command signal is not getting to the socket, your ignition switch or start wire from the switch are bad, or your safety interlock is not closing. In the above case, the ground side of the relay is also dependent on a signal from the body control module, which checks for a "go" indication from the anti-theft system. If the command signal is getting to the socket, but the relay is not clicking, replace the relay.
If you don't have a start relay and you do not hear anything when you turn the key to start, the problem is usually with your safety interlock switch, immobilizer/security system, wiring, ignition switch, or solenoid.Let's first check the full circuit to eliminate the solenoid.
You can check the complete circuit with a simple test light if you don't have a voltmeter. Connect the clip of the tester to a good ground point, such as the big solenoid terminal with a black wire, and hold the tip to the smaller solenoid terminal. The test light should illuminate when the key is turned to "start." While you're there (assuming your solenoid is mounted on your starter), you can also verify that the big red wire to the starter is hot by touching your tester to that terminal. If you are getting 12 volts to the small solenoid terminal but the solenoid is not clicking, replace the solenoid.
An even simpler (though not quite as safe) reverse test to check the starter/solenoid is given under test 2 of the solenoid clicks case near the top of this tip. Run the solenoid jump test, and if the motor does not crank, the starter/solenoid is not working. If you hear only a solid click, the solenoid is probably working. If the starter sometimes works and sometimes doesn't, you may have a dead spot on the starter commutator. In such a case, smack the starter square on with a hammer. If it then works, replace the starter. If the starter turns too slow or overheats, it probably has an internal short or open windings. If you aren't sure whether the starter or solenoid is bad, take the whole assembly to the parts store for testing, or just replace the whole assembly.

If the motor cranks the engine during this test (start circuit is bad), your ignition switch, starter fuse, or relay is bad, the start wire or safety interlock is open, or your immobilizer/security system is activated. We have already discussed the start relay, in case you have one. I cannot cover security systems here due to the large number of them and difficulty in resolving these issues. If your security light is flashing, seek help in deactivating your particular system.
Safety interlock: Most cars built in or after the 80s have an interlock switch to ensure the transmission is not engaged during start. In automatics, the interlock is on the shifter or the transmission at the cable attach point. Try moving the shifter while holding the key in the start position. Most interlocks will also allow you to start in Neutral.
On manual transmissions, the interlock is usually mounted on the clutch pedal. In these cases, it is a simple matter to pull the connector off the switch and connect a wire across the 2 terminals inside the connector. Push in the clutch and try to start the car.
If your interlock is not allowing the car to start, adjust or replace the interlock, as necessary.
Lastly, if everything else works, you are down to the ignition switch. If you are good at electrical work, you can open the ignition switch for repair or at least jump the hot lead to the start lead to verify the wiring is good. If the starter will jump at the switch terminals, you know you have a bad switch. If it will not jump, check the wire from the start terminal to the engine compartment for an open.
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To Order car parts online:--To get heavy discount on car parts .Click this link below:----

http://technoanswers.blogspot.com/2011/05/from-where-to-order-car-parts-online.html

For car error code diagnosis click the link below:---

http://www.automd.com/diagnose/?amdcid=apwldrbrd1

Car no start:--

http://technoanswers.blogspot.com/2011/05/car-will-turn-over-but-will-not-start.html


1 comment:

  1. I have a 1999 subaru forester, it can not start today. The car is auto, 110k miles, awd. In the morning, I tried to start it several times, I can only hear click sounds, but engine did not respond. The battery seems fine, with headlights working fine when key at on. Tonight, I tried to start it again. This time the click sounds disappeared and nothing happened when turning the key. The headlights became very dim and the warning lights (oil pressure and at oil temp) on instrument panel did not show on when key was at on. This is really strange. Any help is highly appreciated. Thank you in advance.

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