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Discussion Starter #1
Car: '96 Honda Accord
Amps: JL 1000/1 and JL 300/4
Wiring: Big 3 done. Kicker Hyperflex 1/0 running to distro 4 gauge Kicker to amps
Battery: Sears Die Hard Platinum
Alt: DC Power 180amp
Mod done to keep alt in 'high output' mode (ELD workaround)

Ok, voltage to my amps seems to be getting low (i.e at higher volume my 300/4 will shut off). I haven't taken measurements yet but I have seen this happen before. My lights of course dim. I have had problems before with this and I thought I had it totally fixed but it seems not. I have upgraded everything I have been advised to (see list above). I am in the 'better alt' vs. more battery/caps camp. I prefer to solve the power problem at the source if possible. The alt is the one area I just can't be sure about. I don't know if it is putting out what it is supposed to. It has been suggested on another forum that I have 'belt slip' but I just don't think that is it. One general question I have is this: Is there something in the alt that controls how fast more current is provided when demand is there? I am almost to the point of wanting to give up here. My system is not that powerful but I seem to have these low voltage problems. I have read about more powerful setups that are on stock electrical that don't seem to have these issues. I would like to solve this once and for all if I can. Help!
 

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alternators have a voltage regulator in them. the regulator will make the alternator produce more current to keep the voltage at the set point, up to the point where it cant make more current and then voltage will sag.

good way to tell if it is a voltage problem would be measurements, sorry :) take a DMM at the amplifier power wire input and then crank it. see what your voltage is on hard bass hits. (if your meter will do min/max, this is easier to see)

I cant imagine the vehicle demands and those two amplifiers are pulling more than 180amps. are you sure on the belt slip thing? is it a standard v-belt or one of those serpantine belts? if you look at the inside of the belt (the side that contacts the pulley) is it shiny or polished looking?
 

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Discussion Starter #3
alternators have a voltage regulator in them. the regulator will make the alternator produce more current to keep the voltage at the set point, up to the point where it cant make more current and then voltage will sag.

good way to tell if it is a voltage problem would be measurements, sorry :) take a DMM at the amplifier power wire input and then crank it. see what your voltage is on hard bass hits. (if your meter will do min/max, this is easier to see)

I cant imagine the vehicle demands and those two amplifiers are pulling more than 180amps. are you sure on the belt slip thing? is it a standard v-belt or one of those serpantine belts? if you look at the inside of the belt (the side that contacts the pulley) is it shiny or polished looking?
I can't either. I will take more measurements. It's weird it seems like some songs that don't have what I would call 'booming' bass will cause more of a problem with dimming. Like for example, I may have more of a problem playing a song like "100% Pure Love" by Crystal Waters than say playing "Late Nite Tip" by 666 Mafia. It's like hard kick drum type hits seem to be more problematic. I don't know. I will take some measurements.
 

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if you have an RTA, take a reading and see if you are peaking a bit in the 60-150 hz area.
 

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Most likely it's a grounding issue or something lame like that. Big 3 does no good if your amp is mounted to a bad spot OR if any of the wires go to a rusty spot on the car.
 

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Discussion Starter #6
I am open to trying a new ground point. Can someone recommend where I should ground on this car?
 

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I've heard that alternator shops can check how much current your vehicles electricaltakes up and maybe they can let you know if your alternator is making rated power.
 

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unabody cars don't exactly have a frame. Where exactly is your amp grounded in the trunk?

Your car should only have had a... I think it's a 70 or 80 amp alternator from the factory. Extra 100 amps should be plenty for what you're running unless you crank it all the time.

As for grounds, I meant more than just the amp ground. On a 96 Accord I think there should be grounds under the engine
1. From the battery to the transmission case (pass side)
2. From the battery to the chassis (pass side)
3. From the frame to the valve cover (driver's side)
4. Frame to thermostat housing (pass side)
5. Frame to accessories (little grounding block, looks like a plastic block with a bunch of little black wires coming out) one on the driver's side, one on the passenger's side

Those should be all the *main* ones. I'd check them out and make sure they're all grounded in clean areas, wires are all good, etc.

Or if you wanna, you could always play connect the dots like these guys
http://www.scionlife.com/forums/showthread.php?t=10785
 

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^^^^ THIS...

If you haven't replaced ALL of these grounds, you've got problems.. it's a 96.. most times the grounds aren't even insulated under the hood...

Freshen all of your grounds around the car you can find and I bet a lot of the problem goes away, I bet you net a few HP and MPG out of it all too..!!
 

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A star ground is MUCH more effective than your standard "connect the dots" approach.
 

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Discussion Starter #12
Right now my ground is on a rear strut tower. Ok my voltage measuring at the amp is getting down to the upper 9v range enough to stop the amp. A couple of weird issues

1. The 300/4 doesn't shut off like it used to when the power dropped too low. I.e. the power light stays on even though it stops playing. Now I have a couple of other 300/4 and one or two of them was repaired by JL Audio so maybe this is a different amp than I had in the car when I had the problem before.

2. So for on the 300/4 only stops playing the 1000/1 keeps playing.

3. My voltage measurements even without music playing are maybe .5 volt lower at the distribution block than the voltage meter I had stuck in the cig lighter. Of course, this could be inaccuracy of my DMM, the cig voltage meter or both.
 

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Voltage drop over a distance is a common thing... that's why it's so common to see people (like me) running 1/0awg mains... It reduces voltage drop over the distance from the alt/battery to the amps..

WHY you are getting as low as 9v at your amps, I simply can't understand right now..

I do know I just found my friends civic, he had the idle lowered to like 650-700rpm...

The alt wouldn't even output that low...

He asked me about it, so I pulled out the DMM... with the car off it tested 12.33.. with the car at idle it was DROPPING and at 12.20.... lol...

As soon as he bliped the throttle and got it above whatever the stock idle was/is.. 14v.. lol
 

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ya, I would be measuring everything with the same meter. meters have enough tolerance (and lead wire resistance) to make that much difference.

that is the reason for your shutdown for sure. anything less than about 11V and you are in the danger zone. anything less than 12V and you are certainly abusing the charging system or you have something broken in the charging system.

considering you have 1/0 cable going from the battery to the back, you are not under gauge there. are you using a similar size for ground? how are you grounding it? scrapped all the paint off and made sure you have a nice shiny place to ground?

FYI, running amplifiers at that low a voltage is harmfull. remember ohms law. P = IE the less "E" you have the more "I" you will pull to keep "P" the same.

so if you have 100 watts @ 12V, that is 8.333 amps pulled through the output devices. drop the voltage to 9 and you will pull 11.111 amps. if the amplifier is designed to produce 100 watts @ 12V the extra 2 amps might not be a big deal. but if it is a 4channel, now you are talking about 8 extra amps. if they dont have enough reserve biult into the amplifier, you may do damage.
 

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Discussion Starter #15
^^^^ THIS...

If you haven't replaced ALL of these grounds, you've got problems.. it's a 96.. most times the grounds aren't even insulated under the hood...

Freshen all of your grounds around the car you can find and I bet a lot of the problem goes away, I bet you net a few HP and MPG out of it all too..!!
Just to be clear you are suggesting that I actually replace all of these not just check them out and make sure they are grounded well?
 

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Just a thought change out your distrobution block out... and what size fuses do you have going to each amp? The small amp should have a 80-100 amp fuse and your 1000/1 should have 100-120amp fuze.
 
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