Switching ON headlights shuts OFF the engine

aargee · 9th March 2010, 14:58

Quote:

Originally Posted by benbsb29

i feel the engine is not switching off, but the electricals are acting up, and as a result the tacho and meters show different readings.

Very sorry Ben; I'm very very confident that the engine has actually shut off & I felt that with my gas pedal, not only once, but several times for atleast 15 Kms drive.

Quote:

Originally Posted by benbsb29

Why dont you open the bonnet, and ask someone to confirm if the engine actually stops running when you turn on the lights? I'm pretty sure it doesnt.

Well, I'm unable to get that now; will test it when I drive back home this evening.

Quote:

Originally Posted by benbsb29

Its definitely the electricals playing up.

Yes

Quote:

Originally Posted by Jaggu

RPM will drop by 50-100 at the max, this is due to the additional load exerted by the alternator, and this happens when you try it at idle reving.

Oh!!! Ok, may be I've not noticed this before.

vasanthn21 · 9th March 2010, 14:59

Quote:

Originally Posted by aargee

Here's the sequence I'll try to explain as best as possible...
1. I'm going to overtake a Tata Ace & I see this biker coming in opposite direction. I want to get his attention that I'm going to overtake this ACE & decide to use dipper to blink my lights.
2. While I overtake the ACE, I pull the dipper & I feel that the acceleration is dropped
3. I'm thinking that the lack of acceleration is my illusion & by now I've overtook the ACE, I leave the dipper OFF
4. Now I notice that the vehicle is gaining acceleration & I got confirmed that the illusion is for real
5. Now I pull the dipper to reconfirm the reality & shocked to see both the speedo & tacho needles falling off; I leave OFF the dipper & everything is normal again.
6. Now I decide to test further & switch ON the parking lights & notice everything is normal again & switch OFF the parking lights
7. After sometime I switch ON the parking light & turn ON the headlights & find the engine shut OFF; Now I'm confirmed that headlights are the culprits.
8. From time to time, say for about 4-5 times, I kept checking for this erratic behaviour until I reach my office for about 15 Kms range.

Note - Steps 5, 6, 7 & 8 were all done when I was still driving

If you are performing steps 5,6,7 &8 while driving, practically the chances of you bumping into someone due to ineffective brakes is more than your car going up in flames.

Anyway... that is not the point.

Hope you can figure out the problem pretty soon. Keep fingers crossed. All the best

bblost · 9th March 2010, 15:04

Aargee, do you need to crank the engine after it switches off.
OR does it get back to life as soon as you switch off the lights.

In a stationary car or if the car is rolling in neutral, I don't think the engine can start on its own. i.e. without use of the starter motor.

srishiva · 9th March 2010, 15:13

You dont experience shudder when the engine switches off with gears engaged?

aargee · 9th March 2010, 15:23

Quote:

Originally Posted by bblost

Aargee, do you need to crank the engine after it switches off.
OR does it get back to life as soon as you switch off the lights.

No I don't need to crank up; Even Rehaan was surprised by this answer; I don't know why.

Quote:

Originally Posted by bblost

In a stationary car or if the car is rolling in neutral, I don't think the engine can start on its own. i.e. without use of the starter motor.

Oh!!! well, what I mean is, say your clocking 50ish on a straight empty stretch; one can shift the gear from top to neutral, but the idling remain & the car keep rolling right? This is what I tried to explain.

Quote:

Originally Posted by srishiva

You dont experience shudder when the engine switches off with gears engaged?

No I don't experience shudders

vasanthn21 · 9th March 2010, 15:34

Your vehicle doesn't shudder when the engine turns off
Your brakes are not ineffective
Your steering behavior doesn't change.

Doesn't look like your engine is turning off. Some other problem.

ElantraGT · 9th March 2010, 15:50

aargee,

This might sound repating the solution but I belive your engine is not shutting off. Instead your Instrument cluster goes for a task due to some electrical malfunction. Since most of the cars are driven by the ECU when it messes up with the electrical the ECU which controls the Fuel Injecton is not responsive to your gas pedal inputs. As suggested by everyone I would recommend you to take the car to a competent electirician and gets things sorted out before testing further.

As everyone has mentioned, the minute engines shuts off, your cars breaking ability will go for a task. The breaks are vaccum boost assisted and the power to the vaccum is taken from the engine itself. So your break pedal will become hard and you have to literally stand on the breaks to slow down your vehicle.

Just a stupid idea for testing, when you rev your engine have the bonnet open and switch on the headlights and have some one see if the engine stops running when you see that the tachos on the instrument cluster is going to zero.

aargee · 9th March 2010, 15:55

Quote:

Originally Posted by ElantraGT

As everyone has mentioned, the minute engines shuts off, your cars breaking ability will go for a task. The breaks are vaccum boost assisted and the power to the vaccum is taken from the engine itself. So your break pedal will become hard and you have to literally stand on the breaks to slow down your vehicle.

Yes, I'm aware of this, but I haven't done this, if I experience the same in the evening, I'll give a try on brakes; I do have empty stretches going home.

Quote:

Originally Posted by ElantraGT

Just a stupid idea for testing, when you rev your engine have the bonnet open and switch on the headlights and have some one see if the engine stops running when you see that the tachos on the instrument cluster is going to zero.

Not a stupid idea at all; since my gas pedal's were going down on acceleration, I was sure that the engine was shut OFF.

Anyway, the update now is, I'm unable to experience the same problem once again; may be it reappears after some amount of considerable driving or engine heat up. I'll keep you guys posted on this.

amitk26 · 9th March 2010, 16:30

One question how old is your battery ?

Since you say everything worked will till there was a armature change by MASS and also battery is changed once but you never elaborated why armature change was required in first place in short span of 3 years and why OEM battery went Kaput 3 years is little too short for both of there.

Answer lies in the extra load you have put.

Now here is my theory

You do have considerable load which is inappropriate for the Wagon R but as you said you almost always use low bean ( 100 W) and rarely use 130W except for short duration like flashing so may be it worked for so many days ( of-course with battery replacement and armature coil replacement with in 3 years).

A 130 W light means almost 10 - 11 Amperes of current depending on what is the Alternator voltage at that point.

An Alternator in car charges the battery which acts as reservoir for high current loads mometerly. So when you flash your headlight a high current is drawn and if your battery is OK your alternator would charge it back after some time , But in case your battery is weak or your alternator is not charging it enough after the flash the charge in battery will dip and it my cut Console / ECU.

Do the following.

1. Check the battery voltage when car is off it should be 12 V
2. Check the Alternator output voltage at idle it should be around 14V.
3. Turn on the headlight while engine is idel and check doe the Voltage across the terminals it should not drop below 13.4 V.
( Both Battery terminal volatge and alternator voltage will be same as they are connnected in parallel)

Now if you observe that there is a voltage drop but your alternator is OK you have following choices.

1. Replace a new battery and keep on replacing it every few months.
2. Do away with 100/130 lights , Legal limit is 55/65 Watts and Normal folks find it OK so may be you just need to change habit.

If above choices are not OK fit an alternator with higher current rating from another car so that it can cater to the 10 -11 ampere more then your current alternator. Also you would need a bigger Amp-hr battery.

vasanthn21 · 9th March 2010, 17:03

AmitK's explanation seems to be the most logical one.

As ElantraGT also mentioned earlier, something is causing the ECU to malfunction, could be battery problem or something else. But, you mentioned that you got the battery checked 5 weeks back right?

Have you checked if the temperature gauge is showing abnormal heating? (around the time when you face this problem?)

LionX · 9th March 2010, 17:34

Quote:

Originally Posted by aargee

Now the question comes as to what extend does it drop? For which I would say, during idling, it drops about 100-150, on 2K upto 100 & at 5K it could be less than 100 RPM. But for sure YES IT DOES DROP & there's a consistency in it.

aargee, I am not clear about the point quoted above. Do you mean the RPM drop as Engine Shut off ??

I believe the Shut off means the engine will stop and the RPM will finally touch 0.

aargee · 9th March 2010, 18:43

Ok, again in the evening when I drove back all the 33 odd Kms, not even once a single time did I experience this problem; infact I'd my headlights ON at some point for more than a minute; used dipper; high beam, low beam everything, but NO, the issue did not crop up.

Now when I took it to the MASS, in their expertise opinion, the issue was isolated to earthing; they said somewhere, somehow there's an earthing happening due to which the engine shuts off & they wanted about a day & half to check the complete wiring;

I'm in no mood to send my car off for a day as my bike is already in workshop; so I softly slipped away for now, hoping the issue should not occur again; but if it does, then I don't have a choice other than sending to MASS.

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