REaudioBuff Posted June 17, 2011 Report Share Posted June 17, 2011 I have a d3400 under the hood of my 2007 scion tc... It charges fine at a nice 13.8 volts with my stock alt... Now my problem is that I have almost a 2 volt drop to the back batteries. I have 2 deka group 31s in the rear of my car with 0 gauge running to it. I have checked the batteries and they rest at 12.6volts each if i pull them out of the car. Right now i have them sitting in my room and just the front battery hooked up and the voltage back there still reads 12.0 11.8 just driving around and will not climb higher... I have never had this problem before and my friends and I have no idea what is wrong. All I can think to do is redo all my 0 guage wiring and go straight from front bat to back for both my pos and neg.... I thought it was my alt at first so i got a new one and its doing the same thing so i really have no idea wtf is wrong. Battery or what??? Quote 1 Crossfire XS v2 15" 2 Deka group31a's 1 XS Power D3400 (under hood) 1 Addictive Audio 500.1 1 Rockford 3sixty.2 4 Crescendo pwx 6.5s 2 Pyle Pro Super tweets 1 Crescendo 1000c4 Kenwood excelon x494 Head unit Big Three upgrade All 0 gauge of course 1 4.56c^ft box @28hz (New Best official db score= 151.2 @ 36hz) Link to comment Share on other sites More sharing options...
BassJunkie Posted June 17, 2011 Report Share Posted June 17, 2011 (edited) Definitely run from the alt to the front batt then from the front batt to the back batts. Not sure about scions but the alt might be computer controlled and thinking the batt up front is charged since it is a better battery it isn't getting worn down as fast especially if its only being used to drive the engine. Good luck Edited June 17, 2011 by BassJunkie Quote 1986 C20 Suburban 9 American Bass XFL 15's B2 M1MKII 14v XS Power Batteries Maxwell Caps Acoustical energy is free. Electrical energy is not you havent lived until you've hit a screw with a router. Link to comment Share on other sites More sharing options...
REaudioBuff Posted June 17, 2011 Author Report Share Posted June 17, 2011 So should i run a run of 0 to the back straight from the alt??? or will that fuck the alt? lol... Quote 1 Crossfire XS v2 15" 2 Deka group31a's 1 XS Power D3400 (under hood) 1 Addictive Audio 500.1 1 Rockford 3sixty.2 4 Crescendo pwx 6.5s 2 Pyle Pro Super tweets 1 Crescendo 1000c4 Kenwood excelon x494 Head unit Big Three upgrade All 0 gauge of course 1 4.56c^ft box @28hz (New Best official db score= 151.2 @ 36hz) Link to comment Share on other sites More sharing options...
Hotdog Posted June 17, 2011 Report Share Posted June 17, 2011 (edited) something is majorly wrong if you have a 2 volt drop from front to back.. should be no more then like .3 1. double check you wiring 2. Check your fusing more info as to how you found your 2 volt drop please Edited June 17, 2011 by Hotdog Quote (NEW) 2004 F-150 Build Log -->http://www.stevemeadedesigns.com/board/topic/192208-hotdogs-f-150-build-log/ 2003 Mercury Mountaineer Build Log --> http://www.stevemeadedesigns.com/board/topic/114380-hotdogs-2003-mountaineer-build-log-20-removed/page__gopid__1602379#entry1602379 2008 Equinox Build Log --> http://www.stevemead...g/#entry1475764 Link to comment Share on other sites More sharing options...
REaudioBuff Posted June 17, 2011 Author Report Share Posted June 17, 2011 I have a Dmm and when i had the 2 batteries in the back hooked up it worked for a month charging at like 13.8-14 so i was fine with that.... then it just started dropping so i unhooked everything checked the ground for resistance in the back where i have it grounded to my back strut... that supported my 7k rms system i had for the last 1.5 years... I measured the voltage in the back off touching the power wire and the actual ground with my dmm while car was running (no batts in back hooked up) and it read 13.8 just like the front... Right now i have it hooked up from the front battery straight back to the amp and it reads 12.0 at the amp and 13.8 up front with car idling.... WTF!!! Quote 1 Crossfire XS v2 15" 2 Deka group31a's 1 XS Power D3400 (under hood) 1 Addictive Audio 500.1 1 Rockford 3sixty.2 4 Crescendo pwx 6.5s 2 Pyle Pro Super tweets 1 Crescendo 1000c4 Kenwood excelon x494 Head unit Big Three upgrade All 0 gauge of course 1 4.56c^ft box @28hz (New Best official db score= 151.2 @ 36hz) Link to comment Share on other sites More sharing options...
__d_a_v_i_d__ Posted June 17, 2011 Report Share Posted June 17, 2011 Any reading below 12.5 is bad on a AGM bat . The lowest resting should be 12.6 ... So something is really bad, a bad wire? Ground ? Check all ur wires ? They are connected to front batt ? Did you try to charge em up ? Quote Chevy Impala Shocker Sigs / TC Sounds 12s Sundown NS-1 | SAX 100.4 Sundown Neos | Dayton Audio Neos ETCCC ETCCC ETCCC My YouTube ---- Subcribe!! Link to comment Share on other sites More sharing options...
Hotdog Posted June 17, 2011 Report Share Posted June 17, 2011 is that at idle with volume on radio set a 0? Quote (NEW) 2004 F-150 Build Log -->http://www.stevemeadedesigns.com/board/topic/192208-hotdogs-f-150-build-log/ 2003 Mercury Mountaineer Build Log --> http://www.stevemeadedesigns.com/board/topic/114380-hotdogs-2003-mountaineer-build-log-20-removed/page__gopid__1602379#entry1602379 2008 Equinox Build Log --> http://www.stevemead...g/#entry1475764 Link to comment Share on other sites More sharing options...
REaudioBuff Posted June 17, 2011 Author Report Share Posted June 17, 2011 idle with radio on 0 is 12.0-12.4 and i wont turn my music on much now cause if i do it drops i have seen 10.8 before doing the (oh shit knob down!!) I have had like 15 systems in this car i know what im doing and i have checked everything i can think of.... I redid the ground wire... I am going to re-run the pos from front to back. The crazy thing is if i dont have the back batteries on the system at all the voltage in the back is still 12.0 and front is 13.8... I just dont know... All fuses are fine all wires are crimped in... I just dont get it... Quote 1 Crossfire XS v2 15" 2 Deka group31a's 1 XS Power D3400 (under hood) 1 Addictive Audio 500.1 1 Rockford 3sixty.2 4 Crescendo pwx 6.5s 2 Pyle Pro Super tweets 1 Crescendo 1000c4 Kenwood excelon x494 Head unit Big Three upgrade All 0 gauge of course 1 4.56c^ft box @28hz (New Best official db score= 151.2 @ 36hz) Link to comment Share on other sites More sharing options...
REaudioBuff Posted June 17, 2011 Author Report Share Posted June 17, 2011 Any reading below 12.5 is bad on a AGM bat . The lowest resting should be 12.6 ... So something is really bad, a bad wire? Ground ? Check all ur wires ? They are connected to front batt ? Did you try to charge em up ? I checked all the grounds I dont think i have bad wires... The batts sit at 12.5-12.7 and i just dont get this... I mean even if both batts are bad... then when i have them off why is the back still not seeing the voltage the front is... I dont get this at all.. Quote 1 Crossfire XS v2 15" 2 Deka group31a's 1 XS Power D3400 (under hood) 1 Addictive Audio 500.1 1 Rockford 3sixty.2 4 Crescendo pwx 6.5s 2 Pyle Pro Super tweets 1 Crescendo 1000c4 Kenwood excelon x494 Head unit Big Three upgrade All 0 gauge of course 1 4.56c^ft box @28hz (New Best official db score= 151.2 @ 36hz) Link to comment Share on other sites More sharing options...
Hotdog Posted June 17, 2011 Report Share Posted June 17, 2011 idle with radio on 0 is 12.0-12.4 and i wont turn my music on much now cause if i do it drops i have seen 10.8 before doing the (oh shit knob down!!) I have had like 15 systems in this car i know what im doing and i have checked everything i can think of.... I redid the ground wire... I am going to re-run the pos from front to back. The crazy thing is if i dont have the back batteries on the system at all the voltage in the back is still 12.0 and front is 13.8... I just dont know... All fuses are fine all wires are crimped in... I just dont get it... that is weird did you test the alt output? Quote (NEW) 2004 F-150 Build Log -->http://www.stevemeadedesigns.com/board/topic/192208-hotdogs-f-150-build-log/ 2003 Mercury Mountaineer Build Log --> http://www.stevemeadedesigns.com/board/topic/114380-hotdogs-2003-mountaineer-build-log-20-removed/page__gopid__1602379#entry1602379 2008 Equinox Build Log --> http://www.stevemead...g/#entry1475764 Link to comment Share on other sites More sharing options...
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