Lights flickering

[malones99]

I have a 99 Suburban Vortec 350. When the the Sub is on the lights flicker. Is it in a rhythm low - high, all lights, headlights, interior, exterior, dash, only when the engine is on. Any thoughts?

 

[SCOTTYINWV]

Have you checked all of tour grounds and connections for the amp? I would try removing the ground, re-sanding the bare metal and reattaching it. That is a free and easy check. Also are your battery terminals tight? I would check those, but it sounds like your amp is drawing too much power. What size amp is sunning the sub?

 

[malones99]

What do you mean by Amp?

 

[SCOTTYINWV]

We are talking about "Sub" as in subwoofer?

 

[magimerlin]

Rule of thumb for amp grounds is to make them bigger, wire size wise, then your positive cable. Make sure all your grounds are metal to metal. I would check your lights ground to. An amp or anything that has a good ground will get power before anything with a bad ground. Just a fact of simple electronic resistance.

Another option after the grounds are all taken care of is to install an inline cap(capacitor) on the positive cable going toward the amp.

A stock battery may be to small of an amperage for your truck. Keep in mind the battery size that is stock is made to be able to basically just start and be used by a stock truck with nothing modified.


Sent from what use to be a great country.

 

[96Z71ECSB]

What do you mean by Amp?

I take it that your suburban does not have a subwoofer/amp installed?
Clean up the battery connections and alternator battery connections and then see if it still flickers.
If it does flicker, then remove the alternator and have it checked. Be sure to tell them what it's doing.
I would bet the alternator is on it's way out.
It would be a good time to do the AD244 alternator modification.
I did it on my '96 and love it.

 

[94Sierra4x4]

"When the Sub is on"

Sub = Suburban. to clarify, I believe he is not dealing with a sound system

Check all your grounds under the hood.

On top of intake manifold by thermostat housing, on pass side frame rail I believe, one on pass side fender beside battery.. Check your ground straps as well

Someone can chime in with where the grounds are located, I can't recall them all

 

[1997chevydriver]

Mine did the same as you and it was the alternator getting ready to take a dump.

 

[malones99]

Sorry guys, yes sub as in Suburban, I have recently changed the alternator, didn't fix it. I will check all the grounds.

 

[SCOTTYINWV]

Sorry for the confusion, yes it sounds like a loose or bad ground. Also was the pigtail to the alt burnt or cracked?