major voltage drops, do i need another alternator?

[Lil Poot 5,000+ posts]

well i finished hooking up my crossfire yesterday, and i've got MAJOR charging issues. i'm running an excessive amperage small case 200 amp alt, with a single 31 series optima yellow top under the hood, all the grounds and power wire is 1/0 gauge, underhood and to the back. it has 2 120 amp fuses, and my diamond has 3 30's.

should this system really be taxing my electrical like that? the amp is hooked up at 1 ohm, but its only turned up about 60%. it pulls enough juice to shut itself off every now and then, buck the car just a little bit, and majorly dim the headlights. does it sound more like i need a 300 amp alternator, or a second battery? i'd kind of rather not do a battery, because it would probably mean taking out one of my backseats, remember this is a ***** am. appreciate any suggestions or comments.

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[XtrmAudioCncpts 10+ year member]

is it a ho alt? or is it just a reg 200amp alt?

 

[jrpro130 10+ year member]

sounds like your pulling a lot of amps...but it shouldn't be that bad.

i used to have an 86 caprice w/ a zz4 swap and a 160 amp alt (from 9c1 police interceptor) with my hifonics 1605d and a kenwood 800 w amp to drive the mids. at full tilt i had bad dimming and my engine would shutter...this was with an extra optima in the trunk too...all 0 guauge wires. I had 2 15" type r's at first (old model)...then moved to 2 12" type r's...the new models. All subs were dual 4 ohms...the amp saw about 1.4 ohms (i had very short 8 guage wires to help w/ imp rise)

maybe its older cars...i know with my truck now the engine comprimises for the alternator losing power and puts the rpms up about 200 rpm. without engine diagnostics your idle speed is always the same and when you try and pull that many amps..of course your eng is going to struggle.

now the difference between the older cars is they don't have that obd that the newer cars have. (thats on board diagnostics)

maybe someone else can explain better...that was just my experience...one car, one setup...4 diff subs //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[digital mint 10+ year member]

From what i've been reading, a few people had problems with their EA alts. You may want to investigate it first. I'm running about the same amount of watts and my alt is 180amp and i have no dimming at all.

 

[Lil Poot 5,000+ posts]

i can test the amount of current its putting out with a clamp meter right?

before, when i had an eD nine.1, and my d5 600.2, i didnt get any voltage drops driving, and only slight ones at idle, although the voltage would drop to around 12 at 750 rpm. at 850 or 900 it was 14.0 and 14.5 by 1000 rpm.

i did do a couple of other things at the same time, i ran a 1/0 gauge wire from my negative battery terminal to the back, a 3way splitter to 4 gauge for the amp gounds, added a 4 gauge line from the battery + to the diamond amp, and have my original 1/0 line from the + to the 2 way splitter for the crossfires supplies. i also added a 1/0 gauge wire from the negative battery terminal to the engine head, and now i've got one hell of a ground loop, worst i've ever heard. any thoughts on THAT, or think it could be related?

 

[bamaboy 5,000+ posts]

2 a3000s and 2 batteries and a 200a HO alt i get hardly no voltage drops what so ever

 

[stones 10+ year member]

The problem seems to have more to do with idle speed.

Before fuel injection car company's put a small Idle solenoid on their carburetors to bump up the idle speed when the A/C was turned on on order to compensate for engine bog. Some SPL competitors have used this to increase their idle speed for better voltage stability during SPL burps, they would simply wire it to a switch on the dash and turn it on as needed. Newer fuel injected vehicles automatically compensate for the extra engine strain.

Adding a second alt or battery would only make your engine bog worse so rigging up a switched idle control solenoid on the throttle linkage may be the solution.

Some pictures of what I'm talking about.

 

[stones 10+ year member]

i i also added a 1/0 gauge wire from the negative battery terminal to the engine head, and now i've got one hell of a ground loop, worst i've ever heard. any thoughts on THAT, or think it could be related?

Remove that ground wire and test the system, possible relocation may be necessary.

 

[knukonceptz 10+ year member]

well i finished hooking up my crossfire yesterday, and i've got MAJOR charging issues. i'm running an excessive amperage small case 200 amp alt, with a single 31 series optima yellow top under the hood, all the grounds and power wire is 1/0 gauge, underhood and to the back. it has 2 120 amp fuses, and my diamond has 3 30's..

Do you have a volt meter? Check voltage with car running, no accessories then with stereo. Massive voltage drop can be as simple as a loose connection. Your system lists a total of 330A possible, I think a second battery would be a good option for you. Without numbers though we are all guessing.

should this system really be taxing my electrical like that?

Yes, 240A sub amp will certainly cause a hell of a drain at idle

the amp is hooked up at 1 ohm, but its only turned up about 60%. .

NEVER say that again, your gain is not a volume control and is not a way to measure the amps power output. You can get FULL power out of amp at MIN Gain with the proper input voltage.

Gain- Having your gain (or rather input sensitivity) turned down, means nothing if you have a high voltage output HU. Gain is used to match your HU's output level and match it to the input of the amplifiers preamp section. Some amps have a protection circuit if you over voltage the preamp. The concept behind the "gain" is that your amps input sensitivity ranges from 200mV to 4V (most common, your voltage may vary).

What most people do not realize is that 4V is on the MIN side of the gain dial. So if you have 8V HU or line driver to one amp your DOUBLING the amps input level at the minimum. So If you have a 4V output HU and modestly set the gain at half way, your going to clip the amp before the input signal from the HU will be clipped. Good radios today will play 7/8th up to full volume (preouts only, the internal amps still ****) of clean music, So if you have 0-30 scale, a 27 should still be clean and you would set your amps from that output level. With your radio putting out clean music and your amp's gain lower you will have a better signal to noise ratio from the amp in return.

So please do not use the old "my gain wasn't even turned up " line ever again

is it a ho alt? or is it just a reg 200amp alt?

Is there a differnce? HO means High Output, what is 200A??

 

[chinny 5,000+ posts]

Probably a bad alt...

 

[Lil Poot 5,000+ posts]

geez, don't take it personal knu lol. let me be a little more specific. my kenwood goes up to 35, i turn it up to 24-25 to bump it hard. the sub output can be adjusted from the head unit from -10 to +10, its at +10, but its not a bass boost. the preamp outs are 5v, i think the amp only accepts up to 4v but i could be wrong, i know it isnt any less than 4. while im no professional, i do have common sense and a good ear for distortion, the rl-p's arent producing any audible distortion, except when the voltage drops really low. if the amp does only accept 4, should i turn down the sub output on the HU to maybe +7 or +8 until i am only getting 4v through the rcas?

chinny, the alternator isn't bad. don't hate on EA because you didn't know how to hook yours up and fried it. it worked just fine for the last 4 or 5 months with my nine.1. i think it may have something to do with the fact that my amps are capable of pulling 330 amps and my alternator is only capable of supplying 200, maybe?

im going to check the voltage out tomorrow if i get the chance, and i think i found the noise problem. hooked up my discman to the amps and the buzzing wasnt there, i know my rca's are good, so im going to pull the head unit soon as i can and ground it straight to the battery. just odd to me that i didnt pull the HU or mess with the dash at all when i installed the new wiring, and had no noise before.

also i'm going to raise my idle from 750 to 950 or 1000, and try to find a smaller pulley for the alternator. hopefully this will be enough. does anyone know where i could find a new pulley for a chevy small block alternator, or would it have to be custom?

edit - just had another thought. i wasn't quite sure what to do with the remote, since now instead of 2 i need 3, 2 for the xfire and 1 for the diamond. i just crimped the single remote lead from the my deck into 3 wires that go to the amps. i'm probably not getting a full 12v to each remote lead, is this alright, or do i need something to amplify it?

 

[Blunt 10+ year member]

your remote should be fine 3 is about the most i ever split it tho. i get a relay hooked up after the 3rd.

 

[knukonceptz 10+ year member]

I dont take much personally, but the gain thing is a per peeve of mine. I just like educating people. Too much misinformation and "urban legends" in and on audio boards. Lots of people try to help, but without proper tools none of can answer your questions properly.

 

[Lil Poot 5,000+ posts]

i have the proper tools, a clampmeter and multimeter.

 

[knukonceptz 10+ year member]

Great, then check voltage at the battery and at the amp as I mentioned above (with no acc and then with stereo) See if there is a difference at those two points.