[stanjohn123]

Originally Posted by R2D2

The battery shop would have been able to test the alternator output for you. Does the battery symbol light up when the engine is on? If yes, it is probably an alternator problem.

Check the battery clamps and cables (both negative and positive ends) for corrosion and make sure they are clean and fixed tight. If these are ok you need to get your car checked by an auto electrician.

Thanks R2D2. The mechanic had come and both the battery and alternator were fine.

The issue was rats knocked out one electrical wire connector from the bottom back side of the engine. As soon as that was reconnected, the car started and everything was fine.

[pcpranav]

Alternators can be repaired, as other Gurus have already commented. In my previous car Xylo, I got a small repair done, details HERE . In each city we can find Bosch / Lucas authorized workshops, and many good Auto Electrical FNG workshops. A nice garage exists just 5 min drive from my home, recently he even meticulously did complete wiring for my Hella aux lights.

On the same lines, maybe a good idea to have a Digital Voltmeter installed in the car to give realtime visibility, many types are available.

[sachinkudva]

Hi all,

I have had a long list of electrical problems with my Fiat Punto since I replaced the music system with aftermarket ones in 2016. (Many threads on team-bhp regarding this but the issue still remains!) After months of self diagnosis, I have realised the music system is not the issue after all. Even after disconnecting the music system and the amplifier from the battery, it discharges in about 20-30 hrs. If i remove the battery leads and leave the car for 4-5 days, the battery charge is intact. So battery is not an issue

I had a alternator problem 2 years back. The battery light came up on the dashboard. Long story short - Fiat quoted 20K for alternator replacement but for 3.5K I got the windings fixed at a electrical garage outside Bosch, Bangalore. The issue was gone for about a year. After which the battery started discharging in 1-2 days - which is the current issue.

I do notice that when the car is running, the headlamps dip when I press the horn, or the power window switch. The instrument cluster backlight is also dim. So do I have a rectifier/diode problem as well?? I am really hoping replacing the rectifier in the alternator will fix my woes.
As of today, I need to run the car everyday for it to be operational. In case I dont run it, even switching it on once a day for 1-2 minutes doesnt help and by the second day the battery is dead.

I did go to a couple of very local electrical guys but they don't understand a word when i say 'diode'! I really need to communicate to them that I need the rectifier checked. But all they know is to check battery voltage with car ON and car OFF - 12.5V when ON and 14V when OFF. And based on this they say alternator is working fine.

[Aroy]

Originally Posted by sachinkudva

Hi all,

..............
I do notice that when the car is running, the headlamps dip when I press the horn, or the power window switch. The instrument cluster backlight is also dim. So do I have a rectifier/diode problem as well?? I am really hoping replacing the rectifier in the alternator will fix my woes.
As of today, I need to run the car everyday for it to be operational. In case I dont run it, even switching it on once a day for 1-2 minutes doesnt help and by the second day the battery is dead.

I did go to a couple of very local electrical guys but they don't understand a word when i say 'diode'! I really need to communicate to them that I need the rectifier checked. But all they know is to check battery voltage with car ON and car OFF - 12.5V when ON and 14V when OFF. And based on this they say alternator is working fine.

Your case points to a rectifier or the voltage controller near its end. When that happens the current leaks through the diode(s) hence discharge in 24 to 48 hours.

Find out car electrical shops that repair alternators and starter motors. They will know exactly what to check and how to replace the rectifier/voltage controller. It is relatively inexpensive.

Till then you either run the car daily or disconnect the battery terminal. There will be two cables, one thick going to the starter and a thin one for powering every thing else. If possible disconnect only the thing one.

[saket77]

I replaced the rectifier assembly along with the holder assembly for about 3k last month on my Zen, made by Denso

Fiat may not be willing to repair the alternator by taking it apart and hence have quoted for replacement of the entire unit. Your only bet is to take it to a good electrician who will check for fault and if that is the real issue, will replace the rectifier unit.

Regards,
Saket

[Kosfactor]

Originally Posted by sachinkudva

As of today, I need to run the car everyday for it to be operational. In case I dont run it, even switching it on once a day for 1-2 minutes doesnt help and by the second day the battery is dead.
.

There was such a curious case reported by one of my mechanic friends. Like you the symptoms were that battery was getting discharged for no reason every few days.

Finally the car was left with an expert electrician for a few days, he finally figured out that there was a door switch wiring that had gone bad draining the battery.

Please fit a battery disconnect switch and use it until the issue is fixed.

[condor]

Less than a month ago, we had taken delivery of a new Trax Toofan. The vehicle had been showing an alert "EDC" on the dashboard, and the initial diagnosis was that it was due to a slightly higher voltage being generated. The vehicle ran about close to 700 km after this, but then things went kaput. Battery drained and vehicle stops suddenly. The alternator was diagnosed as faulty, and Force A.S.S tried to repair that. Any other company would have replaced the alternator straight away. But not sure what were these guys thinking. Took some persuasion to get the replacement. All well now.

[R2D2]

Originally Posted by sachinkudva

I had a alternator problem 2 years back. The battery light came up on the dashboard. Long story short - Fiat quoted 20K for alternator replacement but for 3.5K I got the windings fixed at a electrical garage outside Bosch, Bangalore. The issue was gone for about a year. After which the battery started discharging in 1-2 days - which is the current issue.

My Palio 1.6's alternator gave a problem about 4 years back. The regulator had packed up. It was replaced but after the electrician spent heck of a time getting the alternator out from the far side of the engine between the block and the firewall.

Generally windings can be replaced with parts from the manufacturer. Getting the stator/rotor was wound at a 3rd party is iffy if you look at a long term perspective.

I did go to a couple of very local electrical guys but they don't understand a word when i say 'diode'! I really need to communicate to them that I need the rectifier checked. But all they know is to check battery voltage with car ON and car OFF - 12.5V when ON and 14V when OFF. And based on this they say alternator is working fine.

My first guess is the regulator is bad but given the windings were redone those are suspect too. BTW, the voltages should be the other way around. 14 V when the car is on and approx. 12.5-12.6 V when off. Please check both battery and the alternator windings plus the regulator.

[sachinkudva]

My apologies. That was a terrible typo. I of-course meant 12.5V when OFF and 14V when ON.

So not to worry, I am now an expert in removing the battery and charging it at home. I got my own Bosch Car battery charger since a couple of FNG's I visited showed no patience in getting to the root of the issue so I am living with this issue for a couple of months now. These mechanics just want to blame the aftermarket accessories (Stereo & Amp) without giving a workable solution other than "remove it all". Fiat service centre too returned the car saying there was no issue as they do not want to keep cars for too long. Moreover there are only 3 service centres left in Blr and all are too far for me now.

To rule out the Amp and the Stereo, I got a piggy back fuse and did a neat re-wiring of the REMOTE input to the Stereo and connected a switch in between. All DIY. And I see that only when the head unit is switched on, the Amp is ON. (I can still have a leak though, need to do more tests.)

Last night I was able to get hold of a FLUKE DMM (I have a cheaper one, and the AC current calculation is not correct - basically shows a figure of ~ DC Voltage X 2). With the Fluke I was able to rule out the rectifier/diodes of the alternator. When the car is ON the AC voltage across the battery is ~0.35V. Most alternator test articles say excess of 0.5V should be an issue. I checked the value for my other car (Honda BRV) and it was ~0.2V. So I don't think the alternator is an issue here.

Like Kosfactor mentioned, I may have a bad circuit somewhere else in the car. Guess I will spend an hour myself on doing a parasitic drain test by checking Idle current and removing fuses one by one. Last resort in case this too is inconclusive will be to find a good electrical guy and leave the car with him.

@Kosfactor, noticed your location says Bangalore. Would you happen to know who the expert electrician is? I really need one. Though I guess I am looking more for patience than expertise!

[R2D2]

Originally Posted by sachinkudva

Last night I was able to get hold of a FLUKE DMM (I have a cheaper one, and the AC current calculation is not correct - basically shows a figure of ~ DC Voltage X 2).

Consider buying a reasonably priced clamp meter. Makes measuring current much easier.

When the car is ON the AC voltage across the battery is ~0.35V. Most alternator test articles say excess of 0.5V should be an issue. I checked the value for my other car (Honda BRV) and it was ~0.2V. So I don't think the alternator is an issue here.

I assume you mean ripple voltage? If yes, <0.5 V is good. Any higher can damage the battery and other electrical systems.

Attaching Fluke's handbook, a PDF, for measuring and troubleshooting car electrical and other systems. Some tests will require additional Fluke accessories or instruments. But it gives a good idea of what is to be measured, how to do it and measurement range.

[sachinkudva]

Yes, the ripple voltage. I did go through the Fluke handbook (guess from one of your earlier messages on this or a similar thread). The handbook mentions "connecting the black lead to a good ground and the red lead to the "BAT" terminal on the back of the alternator, (not at the battery)", but that wasn't possible due to the positioning of the alternator in my car.
So, as mentioned in a lot of other alternator testing material on the internet (like this: https://axleaddict.com/auto-repair/A...g-System-Tests), I just checked the AC voltage across the battery terminals.

[vivek.ks]

Originally Posted by princenoble

I know it is late, nevertheless, my experience.

My alternator also got damaged recently (Innova at 85K). It was never dead, taken to service center due to a noise from there. Toyota suggested overhaul and cost was approximately 15K.

Got it done from a trusted workshop outside, Cost about 5k & it was 1 hour job. Vehicle is doing absolutely fine.

In a similar situation for my corolla. Do you have any trusted workshop which you can PE me ?

[Sasanka_Sanga]

What is an alternator:
An alternator is nothing but which generates AC current via DC current by using 2 components which is armature and rotor.

What does an alternator do:
Basically an alternator’s job is to charge the battery and maintaining it t 12.63 volts all the time using engine power via serpentine belt.

Symptoms of a failing alternator:
Alternator
It can be very tricky to diagnose these problems without any tools. Battery problems often seem like alternator problems and vice versa. Some of the most common things that happen are things like your car not starting, your battery going dead, serpentine belt squealing and battery light on. These are the most common, but there are others as well. A Digital Volt Ohm Metrer (DVOM) can help narrow your issue of battery/alternator issues by checking the voltage of battery.

Repairing a bad alternator:
You can either repair it yourself or take it to a repair shop. Alternator repair isn't too hard, but you will definitely need a serpentine belt diagram so that you can put it back on correctly.

To troubleshoot, repair and maintain your vehicle, you'll need diagnostic and repair information that is specific to your car or truck. Just disconnect the battery, remove the serpentine belt, unscrew the alternator and carefully remove the connecting wires and inspect for defects. After inspecting, repair/replace the part and follow the reverse order to install it back.

[AutoSphere]

Originally Posted by R2D2

Consider buying a reasonably priced clamp meter. Makes measuring current much easier.

I assume you mean ripple voltage? If yes, <0.5 V is good. Any higher can damage the battery and other electrical systems.

Attaching Fluke's handbook, a PDF, for measuring and troubleshooting car electrical and other systems. Some tests will require additional Fluke accessories or instruments. But it gives a good idea of what is to be measured, how to do it and measurement range.

Just saw your post today and thanks for sharing the fluke handbook.

Maybe O/T.
I have a weird problem with my VWJetta starter which works well when cold, in the morning. After engine is heated up post driving for a few kms, the cranking is slow and the whole engine shudders while starting. I believe the voltage measurements at the starter motor should give me a clue? The problem persists even after my battery was changed recently.

[a4anurag]

Originally Posted by AutoSphere

I have a weird problem with my VWJetta starter which works well when cold, in the morning. After engine is heated up post driving for a few kms, the cranking is slow and the whole engine shudders while starting.

Check this thread - may help you find the solution to the problem being faced.

Originally Posted by AutoSphere

I believe the voltage measurements at the starter motor should give me a clue? The problem persists even after my battery was changed recently.

May be the alternator isn't charging the battery fully which is why it is struggling to start. Get a multimeter and check for the readings during a cold start and after engine is 'hot'.