Drags And Starts In The Mornings

[sampa]

Hi All,

From last Saturday when I start the car (Wingroad Y11) in the morning it drags and starts. It start the way like the battery is dead. Drag start will not happen when you drive some distance and try to start it again. This happens only in the morning or when you stops the car for a long period of time for instance 7, 8 hours. Though it drags and start for the first time it doesn't drag and start if I start it in the second or third time but if you leave the car without driving and try to start the car after 10 or 15 mints time the drag start will occur again. I service the starter motor. Check the battery as well and check for the any shots using the wire mechanism. It seems like no problem on above mention devices.

Any idea what will be the problem for drag start in the mornings.

Thank you in advance for your thoughts.

Sampa

[BLu3HaZe]

No machan alternator diodes are there to create a stable flow of current without any fluctuations (if you did physics you would be familiar with the concept AC to DC, but its not rocket science just google it machan)

Initially the job of a diode is to send current in only one way but here its used in a different application, as Harshana said the charging IC is the one responsible for the flow of current so if there is such a thing the problem is in the ic not the diodes

I think in Archons case the whole circuit ( IC+ Diodes) must have been attached to the alternator

Yes I did maths, so I do know the principle behind diode bridges But wasn't sure about the alternator circuit. Anyway, in a full wave rectifier, the direction of current flow is also controlled due to the direction of the junction right? Which normally doesn't let any reverse current flow, so was unsure if it was the voltage regulator IC or the reverse biasing of the diodes which stop flow from the battery to the alternator. From what Archon was saying, what I understood was that if one or two diodes are burnt out, they let current flow in both directions at some point, but due to the damping effect of the capacitor, the waveform would be smooth enough to charge the battery when the alternator is running but that'd also allow some current to leak when it's stopped. Just theory though, I've not been able to take apart an alternator and check it though, so people in the field would know better

So the charging IC runs directly on 12V rails? Not very familiar with the system so more details would be appreciated.

[The Stig]

Yes I did maths, so I do know the principle behind diode bridges But wasn't sure about the alternator circuit. Anyway, in a full wave rectifier, the direction of current flow is also controlled due to the direction of the junction right? Which normally doesn't let any reverse current flow, so was unsure if it was the voltage regulator IC or the reverse biasing of the diodes which stop flow from the battery to the alternator. From what Archon was saying, what I understood was that if one or two diodes are burnt out, they let current flow in both directions at some point, but due to the damping effect of the capacitor, the waveform would be smooth enough to charge the battery when the alternator is running but that'd also allow some current to leak when it's stopped. Just theory though, I've not been able to take apart an alternator and check it though, so people in the field would know better

So the charging IC runs directly on 12V rails? Not very familiar with the system so more details would be appreciated.

See machan the problem is when Archon says that he replaced the diodes we dont exactly know if it was just the diodes or the diodes + the charging ic.

Yes initially a rectifying bride would stop the flow of current in the wrong way but what you have to realize is that if such a current is coming towards the alternator the charging ic would be the first to receive it so it would stop it before it reaches the diodes.so if there is a current coming towards the alternator it would be stopped by the charging ic not by the diodes

[Sylvi]

Members,

I read lot about Alternates on this thread I thought I will note down little what I know about same.

Alternators came to Automobiles in early 1960 and at that time they did not have IC Regulator. Regulators then were elector mechanical unit it was a simple circuit Battery Charging light control was on that unit. Alternator Rotor had one coil the Alternator stator had three coil windings with different gauges some were connected in series some were connected in parallel this system was called star connection or delta connection acted as the battery charging circuit.

Most Alternator circuits had 6 diodes some had 9 diodes with different amperage according to the requirement this was depending on the Vehicle.To my knowledge if diodes burn off or they become faulty the diode circuit becomes open so no voltage can pass either way.Winding wire thickness or the Gauge of the wire was responsible for the Amperage of the Alternator. All ends of the windings were connected to diodes. 6 diodes were embedded on to negative and positive plates. Positive plate is connected directly to battery positive terminal. Negative plate is earthed to Alternator.Two plates were insulated for not to connect each other. Diodes wire ends of plates were connected to the stator coil windings.

Alternator is in rotation Elector magmatic regulator starts working.12 volt Battery voltage reaches the 14.5 volts the magnetic coil gets energized and cut off the voltage supplied to the rotor so that the charging rate of the Alternator will be regulated without overcharging the battery. Present day IC regulator does the same action.

There are lot more about Alternators I did not write all.

Sylvi Wijesinghe.

[sampa]

Hi all,

I replace the battery. It was the problem with the battery. One cell has gone off. the battery has only 10V with it when I try to do a cold start. When I dive it charge and can be started as normal So I guess the problem is fixed hope fully and I guess there is no problem with the electrical system which can be a big head ache.

Thank you very much for all the thoughts ,

Cheers,

[BLu3HaZe]

See machan the problem is when Archon says that he replaced the diodes we dont exactly know if it was just the diodes or the diodes + the charging ic.

Yes initially a rectifying bride would stop the flow of current in the wrong way but what you have to realize is that if such a current is coming towards the alternator the charging ic would be the first to receive it so it would stop it before it reaches the diodes.so if there is a current coming towards the alternator it would be stopped by the charging ic not by the diodes

Thanks for the explanation bro

Hi all,

I replace the battery. It was the problem with the battery. One cell has gone off. the battery has only 10V with it when I try to do a cold start. When I dive it charge and can be started as normal So I guess the problem is fixed hope fully and I guess there is no problem with the electrical system which can be a big head ache.

Thank you very much for all the thoughts ,

Cheers,

Good to hear you got it fixed without much trouble. Maybe the mechanic who pointlessly 'repaired' your starter motor didn't check the battery properly.

[Archon]

Well sampa im glad that you've solved it.. seriously sorry guys i just wanted to help sampa and err i screwed up err anyway if i happen to visit our electrician again, I'll inquire about it by grabbing his neck . anyway thanks all who enlightened me and my special apology goes to sampa.

Cheers

Archon

[harshansenadhir]

Well sampa im glad that you've solved it.. seriously sorry guys i just wanted to help sampa and err i screwed up err anyway if i happen to visit our electrician again, I'll inquire about it by grabbing his neck . anyway thanks all who enlightened me and my special apology goes to sampa.

Cheers

Archon

Chill man, we all learn and as I've elaborated in one of my previous post, what your electrician replaced could've the diode place which includes the charging IC, so I don't see a reason as to why you should abuse him..

[The Stig]

Well sampa im glad that you've solved it.. seriously sorry guys i just wanted to help sampa and err i screwed up err anyway if i happen to visit our electrician again, I'll inquire about it by grabbing his neck . anyway thanks all who enlightened me and my special apology goes to sampa.

Cheers

Archon

No harm done mate

Im pretty sure a lot of other members also learned a lot through this thread

[Sylvi]

Members,

Most of our Electritians when you inform a startor motor or Altenator problem they without using Ampmeter and a Volt meter check the system of your vehicle Condition of the battery remove the units and change unnecessary servisable parts. Do trial exprriments to see the problem will come ok at the expence and time of the customer. Very few battery service stations have a battery cell load testing meter all have a hydrometer with battery water.

Automobiles have increased local agents also cannot handle all the vehicles some are imorted by others not the export market vehicles. Usear will have to find out good service and repair stations where there are knowlegeble tecnitions with correct instruments insted of visiting all advertised auto repair stations which had come up inthe past like mushrooms.

Sylvi Wijesinghe.

Edited February 26, 2011 by Sylvi