Big 3 Done, Voltage Drops Still to 9 and Cuts Out

[NhustlaR 10+ year member]

he shouldnt need 1/0 for those amps....

I would go to autozone and get your alt checked (its free and takes about 2 min). If your power is only dropping when the amps are on, it must be a batt/ alt thing.

If your power is dropping without the amps on, you have a wiring problem.

Go down the power wire w. the DMM (batt, then fuse, then the run of wire, then the distro block, then the wires to the amp.... figure out what part of your power wire setup is making the voltage drop

 

[Pyro_By_Nature 5,000+ posts]

do this:
1. change fuse and troubleshoot from there

2. have alternator checked (if it can be done easily and for cheap)

x2 In all reality, 1/0 should not be required for that system.

 

[9512ds 5,000+ posts]

does it do this while driving around 2k rpm's or under a load?

 

[ephyouckay 10+ year member]

^^ i think its doing it when hes idle since he took the vid.

 

[9512ds 5,000+ posts]

^^ i think its doing it when hes idle since he took the vid.

that's what ia ssumed. seems to me like the idle amperage your alt supplies just can't keep up.

 

[ephyouckay 10+ year member]

cant a faulty fuse cause it to cut out too or bad contact with the fuse?

ive had that happen before...

 

[Nexson 10+ year member]

It happens at idle (park) and when driving.

I am goignt o replace the fuse, since I have extras

then ill try to get the alt checked.

 

[Nexson 10+ year member]

What exactly do the guys at autozone check on the alternator?

 

[Street DreamsCC 10+ year member]

do you have a 4cyl. or 6 cyl. the 4 cyl has a real small alternator.

take 2 dmm s put one on the battery and one at the amp.

Play it untill it stops and see what they are reading. If your reading 13-14v up front and 9-10 in back then you got a few problems. you either got bad 4ga wire as in corroided, a screw through it, or you have crap fuse that is allowing some power but not enough or bad connection at fuse holders........

Also did you do a resistance check of your ground wire?If not, put your dmm on ohms. Check it at the amp to the metal where you grounded it. (to compare take the 2 leads and touch them) Next play system and watch meter. When it cuts out is there more resistance? Also check it from amp directly to the battery.

It is not always a power issue it could just as easily be a grounding issue.

 

[Nexson 10+ year member]

oK i am going to go ahead and check the wire and fuse now and replace it, thanks everyone who has helped, you guys are pretty knowledgable.

 

[HCCA 10+ year member]

StreetDreamsCC had the best answer so far. Check all points with an ohmmeter. Better to check out all connections first, than spend $200 on new wire to find it was not the problem!! With a voltage drop to 9 volts....it can't even be the alt. The battery should not allow a drop to 9V on a bass note. You might get that problem after the battery is drained, but it sounds like a grounding problem. Your fuse COULD BE half faulted. That is, it's passing voltage & current, but it might not allow large surges of power. Just a possibility, but I would suspect it only after you checked everything else.

It might not hurt just to get your alt checked at AutoZone, just the same. One last possibility...I had a cell die in my battery. I had juice to play the stereo, lights, power everything else.....I just could not start it. You COULD have a weak cell in your battery. Get it checked, as well, to be sure that it is not going bad. And, finally, a weak contact at the battery terminals could cause this condition. The slightest contact will register acceptable voltage, but if there is not good contact, you could limit the current available to deliver on those hard bass notes.

 

[ThatChevyGuy 5,000+ posts]

i had this problem when i did the big three in my car. The power pole (threaded bolt thingy) coming from your alternator, did you screw the power wire onto it? if so, be sure you used a copper nut, or else you pretty much have no alternator, i drove around like that for 3 days,just had horrible drops, and car would eventually die. I can take a picture for reference if needed

 

[Nexson 10+ year member]

Update:

Well I don't want to speak to soon but I think I may have fixed it with your guys help.//content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

Let me try to explain this the best way. I have the 4 guage anl fuse with the mini 150a fuse. So I first checked out the power wire, I remember when I installed I had to literally cut the 4 guage exposed wire in half to fit into this little ring terminal that would then go into the inline fuse that would be tighten down by the set screw. By doing this I came to the conclusion that i was literally cutting the 4 gauge wire in half at the fuse on both sides. So what I did was cut that inch off and start new, I jacked the sleve a half inch, and twisted the wire really tight so it could fit into the inline fuse, now I had the full exposed 4 gauge wire going into the inline fuse and NOT cut half way to fit into the ring terminal. The set screw still tighten down the wire fine, i did this for both sides and then went ahead and replaced the fuse with a new 150a fuse, since i ordered a small box before.

I got back in the car, the amp pulled 14.0-14.1 with radio off, which was a hair better then my 13.9. I turned on my same song in the video (my control song) and it actually did not cut out, On the hardest hitting parts of the song which the beginning, I only went down to about 12, and it was a fast recovery, keep in mind this was the maxium loudness, and thats what i wanted, because i will probably never play my music like this for more then a minute, but I wanted to know the problem was fixed. So far so good, I will see how it is on my drive to work. I am aquiring the JL cleansweep on Wednesday since aftermarket deck is not an option for the accord (imho). Hopefully everything works out well.

i had this problem when i did the big three in my car. The power pole (threaded bolt thingy) coming from your alternator, did you screw the power wire onto it? if so, be sure you used a copper nut, or else you pretty much have no alternator, i drove around like that for 3 days,just had horrible drops, and car would eventually die. I can take a picture for reference if needed

Thats funny you say that, the copper nut would not come off the bolt shaft, no longer then 20 minutes of me trying it got stripped, 2 hours later I had it cut off, what a nitemare, because I didn't want to destroy the shaft's threads.

I so used a black metal nut, is this wrong? Should I replace it with a copper one? Will it make a big difference?

Thanks.//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[vvblazers777 10+ year member]

I'm not sure about that nut thing, but I'm pretty sure you should have a copper nut on there. And yea, when you cut that wire, it was probally part of your problem. I say replace that nut with a copper one, and your system should be good.

 

[Nexson 10+ year member]

I am going to replace it with a cooper one asap, (when I get home from work tonight, but what is the purpose fo the copper nut?