+1 on the Big 3 and you will also want to check your amp's ground as well. 8awg should be fine for this amp, and the Trailblazer should have plenty of alt to handle a couple hundred watts. Your amp ground should be as short as possible to the chassis, and should be connected to bare metal, no paint. The Big 3 creates optimal power flow between the batt, alt, and chassis

 

my point exactly he should not have much dimming at all... first off you answered each of my 3 questions with the worst answer 1-your car is running when it dims ,2- You did the install, 3- and the vehicle isn't that old. Again I will repeat you shouldn't be having this issue ... if I were you I would fire your installer... go in and use a socket or screw driver and tighten ALL the + connections from the battery to the amp and then all the - connections from the amp to the battery (make sure your ground point is free from paint or rust)

but it is also likely this IS the solution and it is free... from here on though you will have to answer with your wallet most likey

Hey that car has a voltmeter on the dash right? what does it read?

 

I've got 1100w RMS on a stock civic alt and bat with 1/0 wire running to the amps and chassis ground. Cranked it baaaaarely dims the lights. I mean you have to be looking for it to notice. I did exactly what the previous poster said, checked every connection and made sure there was clean bare metal to ground to. Even cleaned the engine to chassis ground.

before doing all that, my interior lights would dim just by putting up the power windows. lol!

I do however have a HO alt sitting on my desk waiting for install.

 

Dont worry about the big 3. that is a huge head ache for you at this point and deff wont solve the problem.

400 watts rms is nothing. i have 500 watts rms in my jetta and doesnt drop the voltage at all.

there is deff something wrong tho. maybe the wrong size battery? i would just check all your connections.

for my truck my electrical started to mess up and io found out the battery was just lose and jiggled when i was driving causing things to dim and stuff.

and idea is to have ur interior light on. shut off ur stereo and everything. go to a save place. and tramp the gas and see what happens. and i mean to the floor. if your electrical burps (goes off and on or dims) then its a bad connection.

and i dont get why people say caps are useless? me and 2 buddies have one each and they hold a charge for you to play with ur vehicle turned off and BEEP when you have to start ur car? i dont see how that "makes it worse" it uses a bit of energy to display voltage. either then that they are usefull.

 

not a huge headache... but the proper wiring and connections would avoid this and many other problems, I would say it is money well spent in most cases (though 0 gauge is serious overkill)


the cap will provide a second or two of sound at 20 watts, a small fraction of a second of power at several hundred watts... they are a voltage source not a power source they have a very limited value and cost as much as a decent battery

 

What? I agree that 0awg is overkill for this install, but I can't agree that the Big 3 is a huge headache that won't solve the problem. The Big 3 delivers optimal power transfer between the chassis, battery, and alternator... Dimming lights=insufficient electrical. Poor wiring=insufficient electrical. OP's issue=insufficient electrical. It's truely impossible to understand whether the Big 3 alone will (or won't, for that matter) fix the problem because we haven't even seen the setup

This statement doesn't mean $#!t... Just because one completely unrelated setup worked in another completely unrelated vehicle doesn't speak at all to the actual issue at hand.

I agree. Bad ground, compromised wiring, improper wiring, or generally poor connections throughout the system seems to be the issue

I'm so confused as to why anyone would do this, ever. If you shut off the stereo, you've just completely eliminated the problem area... You'll never see the lights dim due to the stereo if the stereo is off... And if you "tramp the gas" it's going to INCREASE alternator output, further masking any voltage drop issues. PLUS if the lights got brighter or dimmer when the OP does mash the throttle (good way to blow up a motor too) it suggests a voltage regulator is gone, which are usually integrated into the alternator, not an issue with the stereo system itself... Problem is the lights are dimming when the system is ON, so you can see it makes no sense to do this...

I'm not even going to touch the cap comment.

 

My lights dim too at 300 watts RMS in my 06 Mazda6. They did on my 01 sierra 2500hd (stock alternator but still fairly high amp, and 2 batteries), and before that, dimmed my 91 cavalier.

 

I dont think you understood what I ment exactly.

I am pointing away from the stereo for a second and lets say he didnt have an amp and sub.

In my old GMC my electrical would cut in and out by itself aka dimming when driving without subs or an amp. I didnt even have an amp or sub but the lights would dim and sometimes completely shut off. But it was due to a bad connection at a battery. He also owns a GMC so thats why I suggested this to see if it is EVEN the amp and sub doing this to begin with.

If that makes more sense.

I am not saying this is the case. But it just so happend to my GMC truck and you wouldnt even notcie it was the battery terminals if I had a sub and amp.

I dunno its hard to get what I am saying.

I am more or less saying maybe it has NOTHING to do with the amp and the lights going to the beet is just luck. Becuase the OP never said he tried to see if his lights flickered without the sub and amp on.

 

test the battery. and then test it while running. post your readings. (using a meter) then test what your drop is when the bassline hits. as far as the big 3.. unless you plan on going alot bigger. i would just jump to 4guage. and skip the big 3. no offence to deadlysones but its a waste of money running 1 400 watt amp. look closer at your alternator output. even if the battery is to small. you shouldnt be getting big dimming at 400 watts rms. unless there is a connection problem or your alternator is losing its charging abilities. the big 3 only allows better power flow if your using that much power... telling him to go with the big 3 unless he plans on tossing in another 3000 watts is a big waste of money. bigger wire only means more flow if your pulling the current.. if your not its just a big *** wire..... and 0guage is pricey too.

 

Use 0 Gauge Wire




1) Reduced dimming and smaller voltage drops
2) More stable voltage and better current flow
3) Less strain on your vehicle's charging system

So for those of you looking for a cheap and easy way to upgrade your system and help out your electrical system without adding a high output alternator or an aftermarket battery, this is the modification for you. If you have heavy dimming or are getting large voltage drops during loud bass hits, but you don't have the money to spend on a high output alternator or a battery, upgrading your vehicle's "Big 3" will usually help to reduce and sometimes even eliminate the problems. So without further ado, the "Big 3" wires are:

1) Battery negative to chassis
2) Alternator to battery positive
3) Chassis to engine