Before throwing $ around, where can I start on this problem?

[fatalphenom]

2000 Olds Bravada, stock 100A alt (170k miles-has never been replaced), Delco 75PS battery (new as of October 2013); have only done Big 3 so far.

ZRX3200.1D (which I'm told does not do rated) on two AB XFL1244's @ 1ohm; 1/0 ofc for power wire, all grounds cleaned before install. I know my stuff is starving so I haven't been playing it other than for the day after I installed.

I've wired a voltmeter at the amp to see where it was at, so here's my issue:

Starting vehicle and sitting meter reads 13.8-14.1.

While driving and system on, drops to 12.8-13.3.

Turn stereo off along with other accessories while driving, voltage will get as low as 12.5.

I still need to re-check connection at alternator but I'm positive it is snug. Stock alt is 100A (small for the system I know) and has never been replaced in 170k miles so I'm leaning towards the alt going out.

I realize I need a larger alternator and a nice AGM for under the hood (at least) for the size system I have. But before I go and order an alternator, what can anyone else tell me? I'm looking at Singer or Mechman alts.

What gets me is that even with the system off, the voltage does not go back up at all which is why I'm "thinking" alternator.

I appreciate the help and replies in advance, I've spent alot of time on these forums just using the search bars, I'd just like others' experience and ideas. Thank you.

*edit: alternator is 100A not 105A

Click to read more...

 

[mylows10 5,000+ posts]

The stock alt isn't big enough to even run a 1000 for long But when the alts cold it will show a higher voltage than when hot. But if say the regulator is going bad Singer is the way to go. We make a 250. 275. 320 hp and 350 amp alt for your truck

 

[Dub7sonoma Premium Member]

There can only be two possibilities with your vehicle, bad alternator or the VCM isn't telling the alt to charge. I have never seen a VCM stop telling an alt to charge on a 4.3 ever. And I work at a garage for my 8-5 and have worked at a Chevy dealership for a couple years. I agree with mylows10....bad alt. If you cant afford a HO alternator, pick up a AD244 alt. its a direct replacement for your smaller alt, all you need is a longer belt. Either grab one at the junkyard or buy new. You can get a 145 amp very cheap used and around $120 new

 

[fatalphenom]

Back when I had a 1600w Brutus I had lights dim so its no wonder in this case. The erratic needle on the dash made me wire the digital meter.

I've requested a quote from Singer so I've got that reply in an email I saved. I'm interested in the 275A model (170A idle output), but would like to know what shipping is involved to Michigan 49224. I'm looking at purchasing within the next two weeks.

mylows10, idk if you have received any messages lately but I was watching a youtube video on the XFL's and someone left a comment looking for a seller. I told them to come to the forum and look for your username.

 

[fatalphenom]

There can only be two possibilities with your vehicle, bad alternator or the VCM isn't telling the alt to charge. I have never seen a VCM stop telling an alt to charge on a 4.3 ever. And I work at a garage for my 8-5 and have worked at a Chevy dealership for a couple years. I agree with mylows10....bad alt. If you cant afford a HO alternator, pick up a AD244 alt. its a direct replacement for your smaller alt, all you need is a longer belt. Either grab one at the junkyard or buy new. You can get a 145 amp very cheap used and around $120 new

Before installing the system I didnt have any electric issues (that were apparent) but I suspect the alt could have been bad due to the mileage (170k on OE parts is a long time) and the fact that I played my 1k watt system hard in the past. I can afford a HO alternator and would like to buy the largest I am able to; I also have a 300w 4ch amp and two sets of components to install. Before I do that though, I'm going to sort out my electric issues so that I'm not trying to save a sinking ship in the future. Thank you Dub.

 

[hispls 5,000+ posts]

Before installing the system I didnt have any electric issues (that were apparent) but I suspect the alt could have been bad due to the mileage (170k on OE parts is a long time) and the fact that I played my 1k watt system hard in the past. I can afford a HO alternator and would like to buy the largest I am able to; I also have a 300w 4ch amp and two sets of components to install. Before I do that though, I'm going to sort out my electric issues so that I'm not trying to save a sinking ship in the future. Thank you Dub.

I expect a stock alternator that old would be about ready for replacement. Whether dropping 3-400$ on a HO alt for 1000W is a great investment, particularly with that old/high miles car I wouldn't think so. I'd get the largest one you can find at a parts store with their warranty and invest in the best quality largest battery you can fit under the hood. That would likely be adequate for 1000W. I know a lot of people here have a dog in the fight trying to sell alternators so take any advice here from vendors with a grain of salt.

 

[fatalphenom]

I expect a stock alternator that old would be about ready for replacement. Whether dropping 3-400$ on a HO alt for 1000W is a great investment, particularly with that old/high miles car I wouldn't think so. I'd get the largest one you can find at a parts store with their warranty and invest in the best quality largest battery you can fit under the hood. That would likely be adequate for 1000W. I know a lot of people here have a dog in the fight trying to sell alternators so take any advice here from vendors with a grain of salt.

The 1000w system was years ago. With the ZRX3200.1D I will be well over that, just as long as I can supply the power.

 

[tprj82 10+ year member]

Do you have any local alternator places by you? I used to have a good one when I lived up north and got a rewound from them for like 200 ish with a 1 yr warranty for my old 4.3s it was 200 cold 165 ish hot. Handled my pair of mtx 1501ds and high current ma audio 4 Chan no problems. Also instead of replacing that batt under your hood since its new why not just throw a batt in the back?

ps my old 99 platinum bravada loved that thing

 

[fatalphenom]

Do you have any local alternator places by you? I used to have a good one when I lived up north and got a rewound from them for like 200 ish with a 1 yr warranty for my old 4.3s it was 200 cold 165 ish hot. Handled my pair of mtx 1501ds and high current ma audio 4 Chan no problems. Also instead of replacing that batt under your hood since its new why not just throw a batt in the back?

In the few years working the parts department at a GM dealer I haven't heard of any alternator places around my area. Not to say there isn't but speaking with technicians here about my issue they didnt mention any and these guys know their vendors lol. The reason why I want a different battery under the hood is because the Delco 75PS is a wet style and I'd much rather have an AGM. Not only that, but I'd like to keep the styles the same underhood and in the back. I'm still researching batteries as well but I'm leaning towards getting two KHC1400 or 1200, unless I go with one for the back and a Red Top up front.

 

[mylows10 5,000+ posts]

Back when I had a 1600w Brutus I had lights dim so its no wonder in this case. The erratic needle on the dash made me wire the digital meter.I've requested a quote from Singer so I've got that reply in an email I saved. I'm interested in the 275A model (170A idle output), but would like to know what shipping is involved to Michigan 49224. I'm looking at purchasing within the next two weeks.

mylows10, idk if you have received any messages lately but I was watching a youtube video on the XFL's and someone left a comment looking for a seller. I told them to come to the forum and look for your username.

No I didn't. Also. I'd say that what hi spl is correct about the alt. but even a 175 amp alt won't be to much better than stock. I had a 95 s10 and put a 175 amp alt in it. I could barely keep 2000 rms voltage up When I went to a 200 amp alt I was good tho. But you need to ask your self is the alt investment for a bigger one worth it to you with your truck. For me it was

 

[jasonbillnelson 10+ year member]

Think about it....if you go with a 275 or 300 amp alt....you can run more power down the road if you upgrade again....i'd make a single purchase man. I don't ever plan on running more than 2500 RMS in my ride. Only doing around 1500 now. But when I by my H/O alt, it will be a 300 amp so I'm good to step up the power down the road.

 

[fatalphenom]

Think about it....if you go with a 275 or 300 amp alt....you can run more power down the road if you upgrade again....i'd make a single purchase man. I don't ever plan on running more than 2500 RMS in my ride. Only doing around 1500 now. But when I by my H/O alt, it will be a 300 amp so I'm good to step up the power down the road.

That's what I plan on doing. The price difference on most models I've looked at have been between 50-80 for a few more amps so I figure why not make 1 purchase now rather than another later.

While on my lunch hour I ran the vehicle down the road with the system off. Voltage ran from 13.4-13.8 while running, and hit 12.8-13.5 idle. The closer I got back to work I turned the system on and turned it up to an 'okay' volume (not pounding or anything) and watched the voltage drop anywhere from 12.5-13.1. Closer I got to parking the voltage hit really low around 11.7. Now, at this point my headunit still works and plays..but the touchscreen does not respond. Now I'm really worried that I've messed it up. After parking I popped the hood and checked the connection at the alternator....loose as a goose, son of a biotch! Hopefully I havent done any real damage the the rest of the electrical system. After work I'm going to run idle and see what happens and on the way home (4 miles from where I work) I'll keep an eye on everything.

Are touchscreens finnicky in general or do you think I've done some damage?

 

[hispls 5,000+ posts]

The 1000w system was years ago. With the ZRX3200.1D I will be well over that, just as long as I can supply the power.

Sorry, missed that part. Still, you've got to ask yourself is the extra 250$ or so you'd pay for a HO alt as opposed to a new stock alt a better investment than a 105AH battery or two? How many years do you think you'll keep the truck? A good quality AGM battery should last a few years on warranty and you could use auxiliary batteries in whatever vehicle you buy next, not so much with a big alternator which is likely a total write off if you total or sell the vehicle.

I've run 3K amps off of stock alternator and a couple beefy AGM batteries in the trunk.

 

[hispls 5,000+ posts]

Also I'd be quite suspicious of any 300A+ alternator unless it's really huge. Typical "max power" type BS. Real world output from alternator is very limited by heat and that is limited by the size of the alternator (physically).

More important that the numbers they claim, find a company who has great customer service and is established. Nathan at Excessive Amperage has done me right, and there's a few others who have had consistent good reviews. Anybody can deliver a shiny looking alternator with a big amperage claim, but who will be around a year from now and take care of you quickly if you have trouble?

 

[fatalphenom]

Yes I feel that investing in a HO output will be worth it. I just dumped over $1,500 in repairing the Bravada (I've been a terrible owner the past 6 years) so I definitely plan on keeping it until the wheels fall off. I'm the type of person that would rather spend big money the first time and have options available rather than spending money and creating a bottleneck.

edit: Also in my post above I'm worried that I messed up my headunit. From what I said in that post (my previous a couple of posts up), is my headunit done? I'm hoping that after work it will have 'reset'.

edit #2 : after tightening the nut on the alternator post on my lunch, I went back out when I had time to start it up. Gauge on cluster and voltmeter wire to the amplifier read 14.0 at idle. It's the smallest and simplest things that can cause confusion if you put the cart before the horse! This of course does not mean I will not buy a HO alt, it just means that I have some time before I absolutely need to.

Thank you all for your responses, they've given me more insight as to what direction to go next.