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Car MP3 Modulator, 12V Supply OFF during Starting ... Why !?

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aljamri

Member
Hi,

I'm using MP3 Modulator during my car driving, whenever I switch the car OFF and start it again, the MP3 file starts over from the beginning regardless its previous position.

I’m thinking to overcome this problem but before that I want to know which of the following concepts is the correct one :

1- During the starting of the car, the Battery Power seems to be dropped to a level that makes the modulator to lose the required minimum power.

2- By design, all the power is allocated for the starter at starting process.
 

Reloadron

Well-Known Member
Most Helpful Member
I'm using MP3 Modulator during my car driving, whenever I switch the car OFF and start it again, the MP3 file starts over from the beginning regardless its previous position.
I would venture a guess that is a function of the MP3 player. Yes, during start all accessories are disconnected from power. Well to a point anyway. If I am listening to a CD and turn my truck off (for example overnight) the next morning or start the CD player resumes where it left off. However, the radio for example has two power connections, one is full time for the clock and memory while the other is the main power. If for example the radio is on, during start it shuts down then resumes after start.

Regardless, since the MP3 player starts again from the beginning I see it as a function of the player. How many power connections does the MP3 player have?

Ron
 

aljamri

Member

arunb

Member
No. 1 is more likely, could be because the car battery is old, or the starter draws a high amount of current. I have noticed this in some cars, where there would be a 'gap' in the audio.
 

aljamri

Member
No. 1 is more likely, could be because the car battery is old, or the starter draws a high amount of current. I have noticed this in some cars, where there would be a 'gap' in the audio.
I think Ron is correct, I've tried this in old (my) and new (company) cars and it is the same, because as long as you hold the car key in starting position (spring inforced), the audio will stay OFF.
 

Reloadron

Well-Known Member
Most Helpful Member
Something I have yet to get around to is going out and measuring (maybe chart and record) the battery voltage in my truck during a start sequence. Additionally beyond the standard cigarette / cigar / whatever lighter socket I have a few additional accessory sockets and have yet to figure out if power comes and goes on all of just the lighter / accessory sockets during a start.

As to the MP3 player? Since it has only two wires (+ & -) for power I would still say the start from beginning is just a function of the player? Just my guess.

Ron
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I would imagine it's simply the battery voltage dropping as you crank the engine - originally my car radio didn't flicker when I started the car, but as the battery got older it blanked out completely while starting. I've recently replaced the battery, and now it's perfectly fine again, and doesn't even upset playing of MP3 files from a USB drive whilst starting.
 

RMMM

New Member
If the voltage is dropping, you could use a cap to maintain the voltage on the unit during the startup.

A cap and zener should do the trick.

BUT, I would definitely check the health of your battery, and replace if needed as Nigel Goodwin mentioned.
 

Mickster

Well-Known Member
Most Helpful Member
There could be a more simple explanation:
As more and more accessories began being introduced to vehicles, the ignition/start switch sytem had an extra terminal added, +15A, A as in the letter, not Amps. This terminal was added to reduce current comsumption whilst the engine is cranked and circuits which are not essential to actual engine start, such as supply to the heater, cigarette lighter/power outlets etc are connected to it.
Terminal +15, which supplies the ECM and other necessary circuits, stays connected when in the crank position, whilst +15A disconnects....
 
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