car almost stalls after sub/amp install

[xlar86x]

hey guys gotta few questions. 1991 camaro v6 1.3 auto. so i installed a 10inch sub and a 900wat amp. 4 gauge wire all the way around. i grounded it to the back seat top of the seatbelt harness. the system sounds great. but now my car is on the verge of stalling. i turn the radio down its ok as long as im not running any other electronics, lights heater........ the alternator is pretty new looking if i had to guess no more then a year or 2 old. the battery is a marine battery. looks pretty old. also i noticed that the negative battery cable is actually a terminal for a side mount and the positive is standard type terminal. is that normal? and if its not what are the downfalls of it? also i just bought a optima yellow top deep cycle battery do you think this will fix the issue? and are there any better ground points in the trunk that are easier to access ?

[Paul Huryk]

900w at full power is pulling almost 75 amps of current away from running the motor, which may put the car on the verge of stalling.

Do you know the alternator amp rating?

[xlar86x]

i dont know the amp rating on the altenator.... ill have to look into it

[maroman88]

put that new battery in, fix the battery posts. if you still have an issue, upgrade the alt... i cant imagine the little v6 cars comming with a heavy duty alt like the 350 v8 cars

[xlar86x]

Is it possible to use a v8 alt on a v6 ? This way I don't have to spend like 300$ on a high output alt. and if I can do the swap what year and make can I swap with ?

[xlar86x]

hey guys 1991 camaro rs v6 3.1l. i recently insalled a sub and an amp. now the car stalls when slowing down. i removed the amp and the issue is still there. i replaced the battery with a yellow top. still the same problem. car ran fine before the amp and sub install. i was thinking that my altenator isnt strong enough for the amp and sub. and even tho i disconnected the amp it may have done its damage already to the altenator. however, when coming to a stop if the car doesnt stall it the rpms get low on the verge of stalling but then when the car is completely stopped and it doesnt die it catches idle and holds relatively well. any ideas? im on the verge of buying a high out put altenator to see if that fixes the issue however im not sure . has any one heard of this before? and ive read this has happened to a few people and they never comment on the fixing solution.......

[V]

Th 3rd gens had side mount battery terminals standard.

A v8 alt will not drop right in to a v6, the housing is different in regards to where the mounts are.

The symptoms you are describing are more to do with improper wiring or faulty equipment(stereo based), which can be bad connections or cheap amp. Dont use a capacitor EVER, that's just a band-aid and not a fix. Actually creates more safety issues.

Where does you Batt+ power come from? alt? batt terminal? ring connector or direct?
The ground, did you sand down to bare metal to make a good connection? use a ring terminal, or sandwich the wire? radio shack connectors or gold plated?
What brand wire? same gauge wire both power and ground? brand of amplifier? headunit? how far up is the gain?

We need much more info.

[sweetbmxrider]

Have a mechanic you like? I'd have someone with knowledge and fun tools check it out.

[xlar86x]

its not my first time installing car stereo stuff. but its a 900 watt rockford fosgate amp 1 10'' jl audio sub and 4 gauge all the way around. altenator is stock and battery is optima yellow top deep cycle. did not install capacitor . i didnot ground to bare metal. however i think ive started looking outside the box. ive been researching the symptoms that my car has been having and they are exactly to the 'T' on a bad brake booster. car idle is iradic wants to stall upon braking , soft or hard petal hich i have a soft one but my pads and rotors are worn to hell. the pad sensor is squealing. and the brake booster has a vacum line plus im getting a hissing when i press the brake pedal from under the dash. i think ive possibly come to the conclusion that its a coincidense that this has happened at the time of the stereo install. i dunno what do you guys think????? just remember that this is like my 5 time doing car stereo stuff but still it would appear if that was the culprit . you guys tell me

[WildBillyT]

Check the hoses.

[Tru2Chevy]

Why not just disconnect the power for your amp temporarily and see if the issue goes away?

- Justin

[maroman88]

and fix your brakes, check for vaccum leaks... youre naming all the things you need to do.

[xlar86x]

yea i know theres a long list of things i need to do. is there anything electrically in the car stereo harness that can cause these kind of problems? theres only 1 wire that i didnt connect off the purchased gm harness and thats an orange wire wich is labeled dash illuminator. but there was now where for me to connect it to the sony harness....... any ideas ?

[Fast92RS]

just fyi the stock alt puts out 100 amps. So you probably are overloading the electrical system.

[Dudbird113]

Gonna need a bigger alternator and i know some people run a second battery

[xlar86x]

So I was searching online and came across an idle relearn procedure. I completed the procedure . Now my stalling issue appears to be resolved . However the idle seems a little low. I don't even hear my belt squeal anymore. I even checked with the stereo on full blast heater fan on and lights the works . The car doesn't stall but the idle does spike and drop but barely . On a scale I'd say it's improved about 90%. I had the alternator checked at advanced and it came up good. Also I called numerous audio shops and they said my stereo set up should not require a stronger alternator . Next step is to change plugs and wires . They're due.