hey everyone, i have been having a charging issue for the past couple months in my 4runner. i used to not care because all my audio equipment was old and crappy anyways, and i still had enough power to use headlights/everything else. the issue is this: whenever my truck is idling, such as at a stop light or in traffic, my amps in the back will shut off. i just installed a new system and dont want to destroy the new stuff.

when i am in park or neutral, i am showing 14.4V on the cap. in the back. when i am in reverse or drive, it drops to 12.8 and then continues to drop. i thought it could be a ground issue, so i took off the grounds to both my battery up front and in the back and noticed that the shop that did my wiring forgot to sand down the paint where they attached the ground. i fixed that but the problem is still there. i have had my alternator tested and it read 191amps (had it rewired for 180 several years back). my battery in the back was tested and it read out "charge and retest" which usually means dead battery. i therefore pulled my battery out and connected all the wires so everything would run off my front battery, problem still there. i dont know what it could be but my alternator.... any electrical guru's have any idea? i would greatly appreciate it!

help save the new system!!

 

oh, and if you need pictures of ANYTHING to help diagnos, just let me know and ill take them ASAP!

 

Not a guru, yet, I think you might be on to somethin'. Alternaters don't last forever. Even with the cap, could be history. Esp. if you've been runnin' many of those neato assesories ya got listed there, at the same time. Unless you have an after-market unit that can take it. Oh, PUN intended, why not?

 

im thinking alternator also, but wouldnt it read poorly if it is dying? and i def. have run my winch, headlights and lamps at the same time before, possibly listening to music at the same time also... damn that was stupid wasnt it!

 

how old is the cap? Maybe it (or the volt meter) is bad? I would start by checking voltage at the amp terminals or distro block and at the batt.

 

Sounds like the amplifierss aren't getting enough amperage. What size wiring are you using for the power and ground cables for the amplifiers?

The voltage dropping to under 14.4V is a little suspicious. Get the altenator and capacitor tested by car audio pros.

 

my wiring from my front battery is 1/0 to my rear battery and from there it is also 1/0 to a distributor block with 4 gauge running to my amps. i also have both batteries grounded with 1/0 to my frame. i had heard over on t4r.org that it was my alternator, specifically my voltage regulator because of how the power dropped when i switched to D or R. i figured my alternator was about done anyways so i just went ahead and replaced it see thread here :

https://www.yotatech.com/forums/f2/need-new-h-o-alt-suggestions-106544/

i changed to the 91 toyota mr2 spyder alternator, rated at 130 amps. it wasnt a plug and play, but was close enough to make it worth it. 185$ with a lifetime warranty is hard to beat (at least if you want it immediately) so i just did that. works pretty well, only thing im concerned about is my belt, but i guess if i dont throw it soon ill be in good shape for awhile.