QUICK voltage drop with little power!! WTF!?!?! HELP PLEASE

[snb778 5,000+ posts]

I've got an H.O. alt + optima under hood, Plus Deka G31 in back. I'm runnin only my 4ch. amp right now, and when I turn the volume up to about 30%... my voltage drops right away for some reason!!!

***I just had this same system in my car about 2 weeks ago.. ripped it out, and now putting it back in

This is all with the car on, radio on easy listening level THIS IS WITH OUT MY SUB AMP!!

Under hood voltage car on: 14.15. I started car, took - off, car stayed on

Deka voltage: 14.08

Amp Voltage: 14.04-05

I will turn the radio up about 2-3 volume, and the voltage drops, and the amp (alpine) will cut out and read (CUR)

Both main fuses appear to be good...

Both my grounds are solid... one bolted under hood, one bolted to seatbelt bolt?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

You tell me. only thing I can think of is

A. Fuse behind the radio is ALMOST blown???

Click to read more...

 

[snb778 5,000+ posts]

is there any way to test a fuse on both ends to see if the proper amount of current is passing though?? while the fuse is still hooked up

 

[snb778 5,000+ posts]

ttt??

 

[tommyk90 5,000+ posts]

How low is the voltage dipping?

 

[snb778 5,000+ posts]

it was going down to 13.5, then it would cut out

BUT I GOT IT!!!... for whatever reason.. I disconnected one of the tweeters, and switched the polarity, and now it works fine!!!.. I wonder if there was a tiny strand of wire touching the "other" terminal or somethin...???

 

[snb778 5,000+ posts]

BIGG ISSUE...

Im waiting for someone to help me out here though PM, but here's what the new issue is

I've been having some voltage issues, and i've about given up here...

Apparently for the last few months, my voltage has been dropping down to about 12.5 on the big notes, and I didnt even know this because my amp with the V. indicator light is in the trunk, and I just re-located it to the back seat....Light's don't dim up to i'd say 90% volume. then i get a LITTLE dimming

I have 180A alt, Big 2 done (no block to GND yet..someone cut it)

Bluetop under hood

DekaG31 in back,

just re-grinded all GNDS, all are/were good,

tried pulling speakers to see if there was a short or something, didnt change

Voltage rests at 14.2 car on..

Batts hold 12.9 car off

Tried disconnecting the - terminal on batt. to check alt, car stays on

so im down to the conclusion this ALT. is a piece of shit...

ANY---other ideas would be GREAT!!

 

[snb778 5,000+ posts]

ttt... could really use some help here

 

[cj407]

if you have h/o alt why is your car on no amps on voltage only 14.08...shouldnt it be 14.4....sounds to me like alt is shot....TIME FOR NEW ALT

 

[bball09124 10+ year member]

if you have h/o alt why is your car on no amps on voltage only 14.08...shouldnt it be 14.4....sounds to me like alt is shot....TIME FOR NEW ALT

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

OMG, your alternator is only charging to 14.1V and not 14.4V, you need a new one!!!!!!!

 

[RAM_Designs 5,000+ posts]

if you have h/o alt why is your car on no amps on voltage only 14.08...shouldnt it be 14.4....sounds to me like alt is shot....TIME FOR NEW ALT

wow....just wow.

 

[cj407]

so then bball what could be his problem since he's having such a voltage drop with only a 4 channel operating?

 

[cj407]

shit my lil honda crx stock alt keeps both my batteries at 13 full tilt...14.3 with car on and no amps on...thats out of a 60 amp max alt...so tell me how his 180 amp isnt keeping up with only 2 batteries...??? someone can answer that one?

 

[bball09124 10+ year member]

so then bball what could be his problem since he's having such a voltage drop with only a 4 channel operating?

If his amps are still grounded to the seat belt bolt it may be a horrible ground. Even if he sanded it down well, he may need to ground to the frame or to the front battery. That's the only thing I can think of.

 

[bball09124 10+ year member]

shit my lil honda crx stock alt keeps both my batteries at 13 full tilt...14.3 with car on and no amps on...thats out of a 60 amp max alt...so tell me how his 180 amp isnt keeping up with only 2 batteries...??? someone can answer that one?

Some (crappy) HO alts do not charge at all at idle, only after you get the RPMs up a little bit, so that could be the problem as well.

 

[WOT]

My vote goes to seatbelt ground, car body/frame work best