HU switches off during ignition

[zakaaaaasss]

Friends,

The Head Unit switches off momentarily when you start the car. I'm facing this issue in NHC (faced this in few cars that i owned earlier also). This does not happen in my Matiz. As i understand, the insufficient current from the battery must be causing this. I do not have any power thirsty amp or sub installed and happens even when other electricals in the car (headlights, etc) are off.

This throws up few queries in mind:

• Is the battery capacity incapable of handling the ignition & stock ICE at the same time?
• Do all midsized & large cars without heavy ICEs, have this problem?
• What adverse effect does it have on the HU?
• Is there any remedy for this?

Mods@ Tried searching the forum, but could'nt find similar post. Pls delete if replicated.

[Jaggu]

this is normal and a work around using capacitors was suggested sometime back. couldnt find the post, maybe its in car audio advice thread

answer to your questions:
1 No
2 Yes and NO, its the way the ignition system in car works and not due to ice, workaround is possible
3 Nothing serious i feel
4 yes there are options like wiring the unit direct to battery, capacitors etc, search the forum

[Zappo]

zakaass (sorry if i misspelt that ), do not worry too much on this issue. It happens with almost every car within a few months. It is not at all an issue. Typically happens during cold starts as the self draws a huge load. Or else maybe you made a few quick stop and start routines within a short period. Or else you probably played the audio in a parked car for some time which drained the battery to an extent. There are various reasons like these which cause the HU to turn off for a while when the car is cranked.

The thing to note here is if you drive the car around for a while so that the engine has heated up and then stop it what happens on the next crank after say 10-15 minutes? If the car starts without switching off the audio you are pretty well setup. My car also shows this behavior. But only under the specific scenarios as mentioned above. If the engine is not cold and I have already driven around for a while to have the battery charged up fully this problem does not show up.

OT: While buying an old car one of the points mentioned is to check the health of the battery. The way to do that is to drive the car for sometime (TD) and then once you park it back switch off the engine while the audio is on and then again turn on the engine. If the HU blinks then the battery probably has a problem. It does not get charged up the way it should.

[risga]

Guys, this is not a battery issue at all but designed to prevent loading the electrical system. When the ignition key is turned towards the start position, some of the electrical circuits are cut off, and ICE is one of them.

eg. in my Getz, even the headlights (not parking lights) get cut-off. The car has a clutch lock. So if you turn the key without depressing the clutch, all the circuits cut-off (ICE, headlights, etc.) even though the starter motor is not drawing current.

A work-around is possible but not recommended.

[Jaggu]

@zappo i think you read zakaasss issue wrongly, i think he is referring to the auxiliary power switch off while cranking which is normal in almost all cars.

while matriz had a direct batt connection.

[low_bass_makker]

here is the thread..

http://www.team-bhp.com/forum/ask-gu...power-ice.html (Uninteruppted Power for ICE)

Mods join both the thread as the matter discussed are the same.

[low_bass_makker]

Originally Posted by risga

Guys, this is not a battery issue at all but designed to prevent loading the electrical system. When the ignition key is turned towards the start position, some of the electrical circuits are cut off, and ICE is one of them.

eg. in my Getz, even the headlights (not parking lights) get cut-off. The car has a clutch lock. So if you turn the key without depressing the clutch, all the circuits cut-off (ICE, headlights, etc.) even though the starter motor is not drawing current.

A work-around is possible but not recommended.

100 % correct answer.

[zakaaaaasss]

i guess what rigsa states should be valid....this must be done for preventing the load on electrical system when you are cranking to start the engine....

zappo@ this is present from day one in my NHC and it is irrespective of whether i'm starting the car in cold season or hot season....anyhow appreciate your detailed explaination

jaggu@ no in Matiz the HU is routed thro' ignition and not directly connected to battery.

[Jaggu]

older matiz it was direct battery, have one such specimen in tvm which i use when i visit and is a pain coz player will run once i turn the player ON, ON switch is integrated in the rotary volume control switch. its an oe installation also.

again check your honda city manual it will be mentioned somewhere i guess

[Sam Kapasi]

Originally Posted by low_bass_makker

Mods join both the thread as the matter discussed are the same.

Yaar LBM, kabho toh please bol. Like this "Mods please join the threads." Very bad behaviour.


Baaki bacha problem, toh this is no problem. Many cars are constructed to shut down all accessorial drains and offer focussed power to the starter.

This depends on the car's electrical construction and is perfectly OK.

So in the words of Black Uhuru:

Chill out Chill out Chill out

[DerAlte]

Slight difference. No, the circuits / relays don't deny power to equipment when one turns ignition.

The Ignition switch (KL15 signal) is wired to each ECU/equipment so that each can optionally disable / reset itself. Battery power is still available all the while, otherwise all controls will lose settings (no NVRAM, lower cost; factory defaults are loaded from ROM everytime BAT is reconnected).

This is a convention followed (in ALL cars) from the time that batteries had limited capability and had to be carefully nursed for performance, and other electrics were limited efficiency and power hungry. That way the started gets a chance to use all the juice others let it draw. Well, once set, they haven't changed that, even though batteries are maybe twice as efficient (power density) now.

To all who dabble with software engineering, cars are the best implementations of 'Object Oriented Design'.

Tara ra ra! (Chalo, bol diya)

[Jaggu]

thats lot of information DerAlte: <eyes popped out>

Do guide us more often

[navin]

Originally Posted by DerAlte

Well, once set, they haven't changed that, even though batteries are maybe twice as efficient (power density) now.

well that maybe for 2 reasons.

1. the number of on board gadgets has gone up dramatically
2. lethargy.

[low_bass_makker]

Originally Posted by DerAlte

Slight difference. No, the circuits / relays don't deny power to equipment when one turns ignition.

The Ignition switch (KL15 signal) is wired to each ECU/equipment so that each can optionally disable / reset itself. Battery power is still available all the while, otherwise all controls will lose settings (no NVRAM, lower cost; factory defaults are loaded from ROM everytime BAT is reconnected).

This is a convention followed (in ALL cars) from the time that batteries had limited capability and had to be carefully nursed for performance, and other electrics were limited efficiency and power hungry. That way the started gets a chance to use all the juice others let it draw. Well, once set, they haven't changed that, even though batteries are maybe twice as efficient (power density) now.

To all who dabble with software engineering, cars are the best implementations of 'Object Oriented Design'.

Tara ra ra! (Chalo, bol diya)

ek dum correct hai ji...

the sources in the car have a battery and a remote turn on..like for expample the HU there is a battery wire and a ACC wire which turns on the HU . when the self is cranked the ACC wire current goes off.. also because of the large load of the starterthis causes the voltage drop which will be bad for some stuff thats why they are switched off by the key switch, in addtion to this all the power is given to the starter so that nothing is used in the car and full power goes for starting it.

[saintsinner]

hmmm.. interesting topic..

Accent - when you crank the Car, everything turns off.. headlights, ICE, fan.. every electrical component. and i guess that is good..but then, i feel its bad for the power antenna.. because i see its become really slow and noisy now.. what say guru's?

Scorpio - nothing turns off.. still continues to work.. is it bad??