Alternator, battery, or amp meter?

[dwinters14]

** EDIT: I curiously went back to the alternator listing and right there it mentions using a smaller belt. I am not currently. So first thing I am going to do is get a shorter belt and see if that tightens things up**
My lights flicker (ext and int) with my bass and it's time to fix it. I have been dealing with this gremlin for quite awhile and I'm asking for some thoughts because it's making my truck un-driveable at night. Before I upgrade my headlights I need to know why they are flickering. It did it with the stock alternator/battery/headlights and wiring and it's doing it now with all newly changed parts. I did a CCA test a few months ago on the battery it came back healthy although it may be due again. Someone recommended a CAP but that is a bandaid, and I want to fix the problem.

Mods:
- Big 3 (0 gauge OFC)
- New OE negative battery terminal
- Interstate battery
- eBay high output alternator

Issues:
-Corrosion on negative battery terminal (about a teaspoon after 5 months)
- Lights flickering when bass hits
- Voltage drops when bass hits

I'm leaning towards the alternator being the problem, but I have also read that "regular" batteries cannot handle the draw of a sound system. I would need to upgrade to an XS or something similar. I don't want to swap the alt and it ends up being the battery or vice-versa. Any help or tests I can do to narrow down my problem would be greatly appreciated.

 

[Doubeleive]

** EDIT: I curiously went back to the alternator listing and right there it mentions using a smaller belt. I am not currently. So first thing I am going to do is get a shorter belt and see if that tightens things up**
My lights flicker (ext and int) with my bass and it's time to fix it. I have been dealing with this gremlin for quite awhile and I'm asking for some thoughts because it's making my truck un-driveable at night. Before I upgrade my headlights I need to know why they are flickering. It did it with the stock alternator/battery/headlights and wiring and it's doing it now with all newly changed parts. I did a CCA test a few months ago on the battery it came back healthy although it may be due again. Someone recommended a CAP but that is a bandaid, and I want to fix the problem.

Mods:
- Big 3 (0 gauge OFC)
- New OE negative battery terminal
- Interstate battery
- eBay high output alternator

Issues:
-Corrosion on negative battery terminal (about a teaspoon after 5 months)
- Lights flickering when bass hits
- Voltage drops when bass hits

I'm leaning towards the alternator being the problem, but I have also read that "regular" batteries cannot handle the draw of a sound system. I would need to upgrade to an XS or something similar. I don't want to swap the alt and it ends up being the battery or vice-versa. Any help or tests I can do to narrow down my problem would be greatly appreciated.

I would do some.troubleshooting
As in get a meter and start testing
See where the draw or poor ground is stemming from.
You may need new battery cables (not just a terminal)
The amp may need to be rewired with a very good power and ground cable and ground location
An amp even if it's not a very big one should have 0 gauge direct to the battery and grounded to the body with o gauge also at the closest location
Amp wiring should be ohm.tested
Battery cables should be ohm tested

 

[swathdiver]

Flickering lights is usually a battery problem, a weak battery.

These trucks have a maximum discharge of about 55 amps or so in stock form. The batteries are rated for between 70 and 80 amp hours of discharge (depending on model). Plenty for a stock system, not so much for you audiophiles.

Ebay alternator? What does that mean? Mechman is what you get when you are serious about such things. Wes has one or two in his rigs. @Doubeleive

 

[Joseph Garcia]

** EDIT: I curiously went back to the alternator listing and right there it mentions using a smaller belt. I am not currently. So first thing I am going to do is get a shorter belt and see if that tightens things up**
My lights flicker (ext and int) with my bass and it's time to fix it. I have been dealing with this gremlin for quite awhile and I'm asking for some thoughts because it's making my truck un-driveable at night. Before I upgrade my headlights I need to know why they are flickering. It did it with the stock alternator/battery/headlights and wiring and it's doing it now with all newly changed parts. I did a CCA test a few months ago on the battery it came back healthy although it may be due again. Someone recommended a CAP but that is a bandaid, and I want to fix the problem.

Mods:
- Big 3 (0 gauge OFC)
- New OE negative battery terminal
- Interstate battery
- eBay high output alternator

Issues:
-Corrosion on negative battery terminal (about a teaspoon after 5 months)
- Lights flickering when bass hits
- Voltage drops when bass hits

I'm leaning towards the alternator being the problem, but I have also read that "regular" batteries cannot handle the draw of a sound system. I would need to upgrade to an XS or something similar. I don't want to swap the alt and it ends up being the battery or vice-versa. Any help or tests I can do to narrow down my problem would be greatly appreciated.

What size amp are you running for your bass output. My system has 2 amps totaling 800 watts, and my lights never flicker. I also have just a stock battery. I am assuming that you have a direct connection from your power amp to the battery with the appropriate size wire and fuse.

As @Doubeleive recommended, first do some checking of your wiring and connections to ensure that you do not have a connectivity issue. If you can confirm that you have no connectivity or ground issues, then I'd say that your eBay alternator may be the source of your issue.

 

[dwinters14]

I would do some.troubleshooting
As in get a meter and start testing
See where the draw or poor ground is stemming from.
You may need new battery cables (not just a terminal)
The amp may need to be rewired with a very good power and ground cable and ground location
An amp even if it's not a very big one should have 0 gauge direct to the battery and grounded to the body with o gauge also at the closest location
Amp wiring should be ohm.tested
Battery cables should be ohm tested

I redid my negative cables. Alt to body, battery to body and battery to engine. All 0 gauge OFC. My alt is running 0 gauge straight to the battery for power as well.

My amp wiring could definitely be the culprit as I installed it a few years ago when I was more of an electrical novice and to top it off it's a really crappy "marine" clarion amp with non-standard plugs and connectors. The first one burnt up and this one has a dead channel.

What size amp are you running for your bass output. My system has 2 amps totaling 800 watts, and my lights never flicker. I also have just a stock battery. I am assuming that you have a direct connection from your power amp to the battery with the appropriate size wire and fuse.

As @Doubeleive recommended, first do some checking of your wiring and connections to ensure that you do not have a connectivity issue. If you can confirm that you have no connectivity or ground issues, then I'd say that your eBay alternator may be the source of your issue.

I think it's a 1000w clarion marine amp. Nothing special. Between my two amps I'm definitely less than 1500watts. I have a 4 gauge OFC with a 175a fuse.

I think I will wire in a fuse block from the battery just under the dash, with 0 gauge OFC power and a ground up somewhere on the firewall. Then run fresh wiring from that block to the amps and see how things go.

 

[Doubeleive]

I redid my negative cables. Alt to body, battery to body and battery to engine. All 0 gauge OFC. My alt is running 0 gauge straight to the battery for power as well.

My amp wiring could definitely be the culprit as I installed it a few years ago when I was more of an electrical novice and to top it off it's a really crappy "marine" clarion amp with non-standard plugs and connectors. The first one burnt up and this one has a dead channel.



I think it's a 1000w clarion marine amp. Nothing special. Between my two amps I'm definitely less than 1500watts. I have a 4 gauge OFC with a 175a fuse.

I think I will wire in a fuse block from the battery just under the dash, with 0 gauge OFC power and a ground up somewhere on the firewall. Then run fresh wiring from that block to the amps and see how things go.

you should be able to check the voltage the amp is pulling at the at amp, if it is abnormally high or abnormally low then that would indicate a poor connection somewhere.
I was checking mine one time and it was showing 15-16v and I was like what the heck? I mean you would think wow cool, but turned out the fuse connection was loose as hell and it was barely connected, so it was fibbing and probably pulling high voltage but low amps. fixed that and it went back to normal. Another time I had a bad ground and the ground wire was getting cooked pretty good because of it, moved it to a seat mounting bolt and that fixed it right up.
I would crank up the noise with the engine running, take the meter and read the voltage at the battery post's then compare that what it reads at the amp connections, there should be very little difference if you are running 0 gauge.

 

[dwinters14]

After doing some research I think my RVC is the problem not my battery, alternator or amplifiers. It seems the headlight diming is an issue regardless of OE vs aftermarket with these trucks. My alternator definitely works properly as it fluctuates from 12.7v - 13.8v depending on load. Without the sound system on the lights flicker every so slightly and more so with the bass.

Before I start tearing anything apart I'm going to do a an RVC bypass with this component from mechman

https://www.mechman.com/mm-vc1-2005-gm-2pin-rvc-voltage-controller/

and see if I can crank my voltage up. Even IF my alt was slipping or isn't good, 12.7v isn't enough for my sound system. I notice a significant drop in sound quality as they're designed to push the most wattage @14v+.

If at that point my issues persist I will invest in a mechman alternator as I will already have all the infrastructure to support it.

 

[j91z28d1]

bit off topic but I'm curious, with the rvc system measuring amps all the time. would hooking the amp up to the battery bypass that measurement and the ecm not know what's up?


on another not, doesn't running the headlights and or wipers send the rvc into max voltage mode? could be a easy test before bypassing it


as for alt, a new design 6 dioid 220amp alt low mileage take off can be had on ebay for a 100$ ish shipped. it's a direct bolt on. I'd personally try that before dropping 600$ plus on a aftermarket alt. they don't need to be over driven to put out that power either.

 

[dwinters14]

bit off topic but I'm curious, with the rvc system measuring amps all the time. would hooking the amp up to the battery bypass that measurement and the ecm not know what's up?


on another not, doesn't running the headlights and or wipers send the rvc into max voltage mode? could be a easy test before bypassing it


as for alt, a new design 6 dioid 220amp alt low mileage take off can be had on ebay for a 100$ ish shipped. it's a direct bolt on. I'd personally try that before dropping 600$ plus on a aftermarket alt. they don't need to be over driven to put out that power either.

Regardless of where the power draw comes from, all power goes to ground. That's why the rvc is on the negative wire.

As to your question about the voltage, yes. With no load besides driving and audio my volts are around 12.7v-13.1v. With headlights on it jumps up to about 13.4v-13.8v. I'm sure if I loaded the truck down with wipers and other electronics I'd get over 14v. It will periodically get up to about 14.4v to 14.7v which I assume is it charging.

I agree with you about the alternators as well which is why I want to give the one I bought off ebay a fighting chance to fully power my system. If I still get flicker, I'm going to throw an amp clamp on to see the draw myself and compare that with what the alternator should be putting out.

 

[Doubeleive]

Regardless of where the power draw comes from, all power goes to ground. That's why the rvc is on the negative wire.

As to your question about the voltage, yes. With no load besides driving and audio my volts are around 12.7v-13.1v. With headlights on it jumps up to about 13.4v-13.8v. I'm sure if I loaded the truck down with wipers and other electronics I'd get over 14v. It will periodically get up to about 14.4v to 14.7v which I assume is it charging.

I agree with you about the alternators as well which is why I want to give the one I bought off ebay a fighting chance to fully power my system. If I still get flicker, I'm going to throw an amp clamp on to see the draw myself and compare that with what the alternator should be putting out.

it's pretty unlikely your RVC causing the issue, if it was there would be a code for it.
IF you really suspect the RVC simply unplug the sensor, this will make everything default
Also if you are using a Tech2 or any other scanner capable of reading the RVC status, then you can test it for functionality.
been down this road already, pretty deeply actually. I suspected the same at one point but it was a bad battery which caused the RVC system to not operate as designed.
determined this after fairy extensive testing, new cables, new rvc sensor, etc,etc. The battery had a bad cell would charge up but would drain pretty quickly and caused the RVC system to think all was hunky dory, it made the RVC think the battery was fully charged and would stay in "economy mode" even if I had every single possible thing turned on that could be turned on
been down the bad alternator road too, the "ebay" alternators I bought in the past were garbage