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2002 A4 1.8t alarm horn

Posted: Fri Dec 19, 2008 12:52 pm
by thedeal7235
so my factory alarm backup horn has gone out; i saw a post in Audi where a guy took his apart and replaced the batteries-but, they no longer make these type of batteries, so im trying to wire together 2 nimh 3 cellbattery packs, but when i took the heatshrink off the first one i cant tell if they wired them parrell, or series, im guessing series, cuz when i measure each cell individually it shows 1.6-1.9 in dc volts, which means, i think, i would wire both packs together posi 2 posi, negi to negi, then solder to alarm pcb board in conjunction with its proper polarity- or, is it possible, they used a combo of series/parrell, which means i cant wire the 2 packs together? any help would be appreciated-
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Posted: Fri Dec 19, 2008 1:56 pm
by thedeal7235
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i think these may be better pics-

the actual horn/siren

Posted: Fri Dec 19, 2008 1:56 pm
by thedeal7235
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Posted: Fri Dec 19, 2008 5:12 pm
by thedeal7235
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ok the dmm does not lie- IWAS WRONG!- each battery pack is wired in series, because as i measured each cell the center kept coming up negative, so i looked closer and bam, as u can see, and forgive my schematics, they are all series for these , so , per my schematic, adding the 2 batt packs together in series, in theory mind you-cuz i dont really know?, should increase my volts to 7.2(per audi specs-keep my mah the same ), i just dont know if its safe or not-i would think YES1 but still waiting for someone with more knowledge to do so, and thank you

Posted: Fri Dec 19, 2008 11:07 pm
by thedeal7235
ok so , it worked!!! kind of, btw Jacampb2 thanx for all knowledge- i figured some of the issues out along the way, but also with some tutoring from Jacampb2!!! ( sometimes i think he waits 4me to c if i can figure it out first-that way i can become INDEPENDENT! :wink: .. any ways, it definetly needed the new batteries, however, once plugged in , the alarm horn/backup battery(its what audi calls it-but , its a siren-and they call it that b/c if the main battery is cut, it still has its own power-the siren just sounds like voice coils rubbing together really hard, now im gonna leave it in for a few days, and see if it re-gains more strength-but im sure its gone, so if anybody out there has an old vw(used same part No.), or audi and wants to get rid of theirs please let me know-ill post more pics of it tomorrow, as its late and actually interesting how bad the pcb was/is b/c of oldleakage

Posted: Sat Dec 20, 2008 11:35 am
by thedeal7235
ok, pics of the siren pcb, as u can see it leaked for a long time, cant believe it didnt go thru the board, the siren went off once this am, so mayb its building back up-if not, i may buy a cheap aftermarket, and use its power, ground, and tie into the existing power ground of siren; the audi alarm has power, ground, remote; saw a guy on youtube who did it this way-still beats paying the dealer 263!!!!
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u have to break away the existing battery tabs @ the bottom of this part 2 make room for the new batteries-dont know whats up with my camera, keeps taking blurry pics :evil:
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