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on an AVT TV Tuner (and I think pati din sa standard na mga stereos sa vehicles), the electrical diagram (sa power supply) consist of GND, +12V, ACC...
the GND and +12V - sa pagkaintindi ko serve as the main supply....
but the ACC? para san to? kung may GND and +12V na, mag on na sya di ba?
or is it pag +12V and GND lang ay laging ON na yung appliance (in this case TV Tuner) and it is the ACC that triggers On and Off (bukod pa shempre mismo sa On / Off switch ng pinaka unit)?
Tama po ba?
The HU gets its power from the +12V line and Gnd. And as you correctly pointed out, gets a trigger signal from the Acc line. This is so so that the radio switches off when you turn off/remove the ignition key. The reverse is also true (depending on the last state of the HU at the point when you turned off the key).
Aside from that, the +12V and Gnd connections are there to make sure that the settings are properly maintained, especially for those units which are still using volatile memory (RAM for example). Try setting a few configurations and remove the +12V connection,- these will disappear.
Of course, those using non-volatile memory (flash for example) may not need the +12V connection.
15.9K:apple:
looking at the internet for the connection diagram nung AVT TV Tuner.. I see na yung ACC ang naka linya na may fuse... question uli.. bakit yung fuse naka linya sa ACC at hindi sa +12V?
last time I tried to troubleshoot yung AVT TV Tuner sa car.. all i did was to get voltage across red wire and black wire... red wire yung naka linya sa fuse... at that time, I assumed that the red wire was +12V.. now mukhang may sariling color code pala... kung base sa bagong AVT TV Tuner connection diagram.. the fuse is on the ACC line... then.. dapat pala I have to double check the wirings uli...
dapat pala ginawa ko... check the voltages when the key is on OFF, at ACC and then again at ON and STARTED... ang ginawa ko last time was just get the voltage at ON (started)....
balik sa question.... so ACC ang nag trigger ng ON ng unit... pero once na nasa ON na ang susi may signal pa rin sa ACC?
Yes.Quote:
Originally Posted by wowiesy
In most cars, it may temporarily get cut off when you turn the key further to START the engine. This is by design so that all battery power is diverted to the starter and ignition system. But once the key goes back to the ON position, the accessories will also power back up.
yung ACC means accessory.. lahat ng accessory ng vehicle like cigar lighter and stereo mag ON when the key is at ACC... now sa wiring ng mga stereo... yung 12V (red) naka connect yan sa 12 line ng kotse (hindi dumaan sa key ignition switch) same yan ng linya ng dome lights. that serves for your car stereo memory, low current din yan.. yung ACC 12V (yellow) dumaan yan sa ignition switch, yan ang direct source ng stereo... high current yan mga 10amps.. kaya may separate fuse yan minsan pero pwede din wala kasi may fuse din yan sa main block mo...
yung naka dumaan sa ignition switch, mag cut off yan pag nag start ka.. pero yung mga 12V line hinde.. kaya hindi nabubura ang memory ng stereo mo pag nag start ka...
I think the yellow wire is the one directly connected to the 12V(+)
The red wire is the one connected to the ACC.
So you must find the wire where it supplies 12V(+) when you turn the key to Acc
You can use this link for reference: Wiring diagram for Pioneer KEH-2650