How to diagnose between starter or solenoid as problem?
#1
Racer
Thread Starter
How to diagnose between starter or solenoid as problem?
Turn key
Click
Headlights do not dim at all
No crank
This has happened three times now, about a month to six weeks apart. Eventually it starts exactly like normal. I can't put my finger on exactly what I did between "not crank" and "crank like normal" but it wasn't anything significant, that's for sure.
Tonight I cleaned the battery terminals, but they actually looked very good. Looking back, I should have checked how tight they were before taking the cable off, but I didn't. Not sure whether a loose cable could explain these symptoms.
I was thinking this was starter or solenoid? Any thoughts on which? Any other diagnosis consistent with the symptoms?
Click
Headlights do not dim at all
No crank
This has happened three times now, about a month to six weeks apart. Eventually it starts exactly like normal. I can't put my finger on exactly what I did between "not crank" and "crank like normal" but it wasn't anything significant, that's for sure.
Tonight I cleaned the battery terminals, but they actually looked very good. Looking back, I should have checked how tight they were before taking the cable off, but I didn't. Not sure whether a loose cable could explain these symptoms.
I was thinking this was starter or solenoid? Any thoughts on which? Any other diagnosis consistent with the symptoms?
#2
Turn key
Click
Headlights do not dim at all
No crank
This has happened three times now, about a month to six weeks apart. Eventually it starts exactly like normal. I can't put my finger on exactly what I did between "not crank" and "crank like normal" but it wasn't anything significant, that's for sure.
Tonight I cleaned the battery terminals, but they actually looked very good. Looking back, I should have checked how tight they were before taking the cable off, but I didn't. Not sure whether a loose cable could explain these symptoms.
I was thinking this was starter or solenoid? Any thoughts on which? Any other diagnosis consistent with the symptoms?
Click
Headlights do not dim at all
No crank
This has happened three times now, about a month to six weeks apart. Eventually it starts exactly like normal. I can't put my finger on exactly what I did between "not crank" and "crank like normal" but it wasn't anything significant, that's for sure.
Tonight I cleaned the battery terminals, but they actually looked very good. Looking back, I should have checked how tight they were before taking the cable off, but I didn't. Not sure whether a loose cable could explain these symptoms.
I was thinking this was starter or solenoid? Any thoughts on which? Any other diagnosis consistent with the symptoms?
The click (if it is coming from the starter area) means that voltage is being sent by the engine control module to the starter solenoid, which is pulling the starter motor gear into the engine (the click) and sending the voltage on to the starter motor, but the motor is not turning over. You can then try taking the handle of a hammer and reaching up and poking the starter motor hard. If it then starts immediately you know the windings in the starter motor are failing and the starter motor must be replaced.
Winding failure will get progressively worse until one day it won't start no matter how hard you beat on it.
#3
Racer
Thread Starter
If this were a battery or battery connection issue, wouldn't the headlights dim as the starter tried to draw current?
Just got estimate from two Lexus dealers -- starter replacement $846 to $1006. Good lord, do you have to pull the engine to get to it?!?
Just got estimate from two Lexus dealers -- starter replacement $846 to $1006. Good lord, do you have to pull the engine to get to it?!?
Last edited by JohnnyCake; 09-12-13 at 07:23 AM.
#4
Buddy
#5
You've probably done this but check to make sure all electrical connections are solid. In particular, check to make sure that starter's ground cable hasn't loosened up, upstream from the starter. On an older car in salt country rusted ground connections to the chassis were frequent problems that caused people to change batteries, starters, etc when all that was needed was a solid ground.
Usually, bad spots on the starter won't give you a click when the solenoid kicks in - it's just dead. Ignition suggestion is good. also check the ground straps leading from the battery. Sounds like insufficient current to me, even though the problem is inconsistent.
Usually, bad spots on the starter won't give you a click when the solenoid kicks in - it's just dead. Ignition suggestion is good. also check the ground straps leading from the battery. Sounds like insufficient current to me, even though the problem is inconsistent.
#6
Driver School Candidate
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Same issue here, intermittent with no consistancy i.e. it only happens when cold or hot. There are 4 or 5 posts about this with no fix mentioned. I could think of a few things it could be, 1 - Ignition Switch, 2 - Starter Relay, 3 - Neutral Safety Switch, 4 - Ground Wire. I am going to get a relay and start there since that is a $25-35 part. I'm sure that the ignition switch is a pretty penny but I really do think it is the culprit. I don't know if it's just in my head but when I twist the key with a little more force it never happens, it seems to happen when I just half *** push it forward and am not thinking about it. I am taking the car in for the airbag recall tomorrow and am going to ask them to take a look at it an tell me what they think it could be, my luck it won't happen when they try it. Not that I have a whole lot of faith in the dealership as they tried to sell me new catalytic converters when it was an exhaust gasket issue the last time I had them diagnose something, $20 vs $2300. If I get any good info, or am able to resolve the issue I will post it here. -Chris
#7
Racer
Thread Starter
The ignition switch (and Mister Blister's bypass idea to test) is interesting, but I can't reconcile the idea that there is the click (presumably solenoid, right?) meaning that the switch is sending a signal. The lights not dimming seems to eliminate the battery unless somehow the car is smart enough not to try to start when there is low flow from the battery. Dang, this is frustrating!
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#8
The ignition switch (and Mister Blister's bypass idea to test) is interesting, but I can't reconcile the idea that there is the click (presumably solenoid, right?) meaning that the switch is sending a signal. The lights not dimming seems to eliminate the battery unless somehow the car is smart enough not to try to start when there is low flow from the battery. Dang, this is frustrating!
Your ignition switch is spring loaded so when you first turn switch to on your radio nav etc lights go on. Try turning key to on first then a second later turn to crank. If you still get no crank I would then try the luxlink and see if you can replicate the problem. If not then I think your issue could be the ignition switch or the grounds to the solenoid relay etc. The luxlink has relays that complete the start circuit and it by passes the turning of the switch. I think you will get to the bottom of it.
#9
I suggested have the battery and alternator checked to be able to set that aside as an issue. A battery can deliver enough voltage to move the solenoid but not have enough voltage to turn over the starter motor.
You describe a click. If the click is the starter solenoid engaging then the problem cannot be the ignition switch.
The starter solenoid does two things: Physically moves the gear on the starter motor into contact with the engine flywheel and it closes a set of contacts to deliver voltage to the starter motor.
You can't deliver voltage to the solenoid (the clicking sound) if the ignition switch is not working and completing the circuit - period.
For those who say if the windings in the starter motor are bad you will hear nothing, you are forgetting the sequence. The solenoid is moved FIRST, which closes contacts and THEN the starter motor is energized. Even if the windings were totally removed from the starter motor this would not affect whether the solenoid moves and makes a clicking sound.
I cannot hear your click, so I can't tell you the clicking sound IS the starter solenoid that is engaging. But IF it is, forget the ignition switch being a possible reason for the starter motor not turning over.
If the solenoid is moving AND the starter motor is not turning, either it is not getting enough voltage (could be battery or ground issue) or it is bad.
You describe a click. If the click is the starter solenoid engaging then the problem cannot be the ignition switch.
The starter solenoid does two things: Physically moves the gear on the starter motor into contact with the engine flywheel and it closes a set of contacts to deliver voltage to the starter motor.
You can't deliver voltage to the solenoid (the clicking sound) if the ignition switch is not working and completing the circuit - period.
For those who say if the windings in the starter motor are bad you will hear nothing, you are forgetting the sequence. The solenoid is moved FIRST, which closes contacts and THEN the starter motor is energized. Even if the windings were totally removed from the starter motor this would not affect whether the solenoid moves and makes a clicking sound.
I cannot hear your click, so I can't tell you the clicking sound IS the starter solenoid that is engaging. But IF it is, forget the ignition switch being a possible reason for the starter motor not turning over.
If the solenoid is moving AND the starter motor is not turning, either it is not getting enough voltage (could be battery or ground issue) or it is bad.
#10
Racer
Thread Starter
Question: If the starter motor was not getting enough voltage/current to turn, wouldn't it still take all it could get during the attempt? And if that's true, shouldn't the headlights dim during the attempt if it were a battery issue?
#11
Lead Lap
Good question. I don't have the answer, though your logic sounds right to me.
You might have someone stick their head under the hood when you turn the key and have them identify where the click is coming from. That should help confirm whether the click is coming from the solenoid.
You might have someone stick their head under the hood when you turn the key and have them identify where the click is coming from. That should help confirm whether the click is coming from the solenoid.
#12
Thanks for your very logical analysis. I definitely comprehend what you are saying.
Question: If the starter motor was not getting enough voltage/current to turn, wouldn't it still take all it could get during the attempt? And if that's true, shouldn't the headlights dim during the attempt if it were a battery issue?
Question: If the starter motor was not getting enough voltage/current to turn, wouldn't it still take all it could get during the attempt? And if that's true, shouldn't the headlights dim during the attempt if it were a battery issue?
There are a number of different modes of failure for the starter. A mechanical failure would include the armature and other moving parts where bearings or bushings wear out, causing high friction or binding. This results in slow cranking. Obviously this is not your problem.
Another failure mode is when the insulating varnish on the winding wire in the coils begins to fail, leading to turn-to-turn shorts in the windings. These connections can be intermittent and striking the starter can sometimes jar a connection. Winding shorts can change the electrical nature of the coils and often increases the electrical draw of the starter during cranking. If the headlights are on they generally dim during cranking.
Another common failure mode is the brushes that make electrical contact with the commutator on the armature (the part that spins inside the field coil) and turns the starter gear which makes contact with the flywheel. When the brushes become worn they do not make contact. The solenoid engages which moves the gear into contact with the flywheel and closes the contacts to allow current to flow to the starter motor, but the circuit in the starter motor is not complete because of the worn brush,therefore no current flows to the starter motor and the lights will not dim (your question).
Often after repeated attempts you can make contact across the air between a brush and commutator and the starter will begin to turn, but this high resistance contact typically causes pitting in the brushes and makes the contact worse as time goes on. Also, if the battery voltage is low, it is that much harder for the contact (spark jump) to be made through air.
One way to test if this is the problem (not completely reliable) is to strike the starter motor hard while the key is turned and the solenoid has closed. Sometimes the brush is jarred and will make contact and the starter motor will begin to crank. A more reliable method is to probe the terminal connections on the starter motor with a multimeter while turning the key. If you hear the solenoid close and 12V or more appears between the terminals on the starter motor you know the starter motor is receiving voltage and is the point of failure due to a bad connection internally not completing the circuit.
Striking the starter was easy on older cars as the starter motor was usually visible and directly accessible from either above or below the engine. But in modern engine compartments, especially V8s, space is at a premium and the starter can be buried below other components, making the "strike" test as well as connecting test probes to the motor terminals to test for the presence of voltage nearly impossible.
Last edited by SC43052; 09-14-13 at 02:07 PM.
#13
Good question. I don't have the answer, though your logic sounds right to me.
You might have someone stick their head under the hood when you turn the key and have them identify where the click is coming from. That should help confirm whether the click is coming from the solenoid.
You might have someone stick their head under the hood when you turn the key and have them identify where the click is coming from. That should help confirm whether the click is coming from the solenoid.
Mainly because, if he takes this advice...*I'm* the gonna be the "someone" with his head stuck under JohnnyCake's car while he's cranking it!!
...And I've already climbed inside his trunk. I think that's enough for one friendship.
#14
Lead Lap
LOL, sorry Habious, I didn't think about the untentional consequenses.
How about standing near the car with the hood up and listening to determine where the click comes from?
How about standing near the car with the hood up and listening to determine where the click comes from?
#15
Lexus Test Driver
Thanks for your very logical analysis. I definitely comprehend what you are saying.
Question: If the starter motor was not getting enough voltage/current to turn, wouldn't it still take all it could get during the attempt? And if that's true, shouldn't the headlights dim during the attempt if it were a battery issue?
Question: If the starter motor was not getting enough voltage/current to turn, wouldn't it still take all it could get during the attempt? And if that's true, shouldn't the headlights dim during the attempt if it were a battery issue?
It could be a bad solenoid not passing juice to the starter motor, the wiring to the starter motor or the motor itself. There's not much else.