I installed a Sony amp and a 12" MTX subwoofer in my car, it was working great and hit pretty hard...until now.

It keeps shutting off...the light on the amp doesnt go out, but it dims. If i shut the ca off and turn it right back on it works again..but not always. I have it bridged also.

Could it be a bad connection somehwere..maybe grounding out or something? Any ideas?
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i would re-check all your connections.. but it sounds like its getting too hot or something and shutting itself off (thermal protection).. where are your amps mounted? my friend has a Sony amp and on 100+ days when he would turn it up really loud (his amps are in the trunk) the bass would hit.. then cut off.. then when it cooled down it would hit again.. then when it heated up it would shut off.. pretty crappy if you ask me...

is your wiring the appropriate thickness/guage? how big is the amp? I'd use a minimum of 8 guage... I run 4 guage on mine.... after you check all your connections and verify that your wire is thick enough to handle the power, make sure your amp has good ventilation..

other than that.. i dunno..

 

The thing I dont get, is why after I sht the car off and restart it (2 seconds later)..the amp comes back on. If it shuts off and I dont restart the car..it doesnt come back on..even if its 30 minutes later of driving.

Also, I used teh same amp a while back to run 2 12" woofers wired in series and never had a problem with it shutting off.

 

Ok..I was just out at my car...and its been sitting for 1.5 hours...the amp turned one..but no sound from the woofer.

The light on the amp is on, but its dim..not as bright as when the sub is working...whats the deal?

 

my honest guess after working in the industry for years is that after you check all your connections, power, ground, remote. adn everything is fine.

You hvae a bad amp. it happens. it might have been caused by putting too much of a load on it or not supplying ehough battery juice.

IM so i can try to help you out some more. let me know exactly what you have and how it is wired up.

 

What gauge wire are you using? How long is the power line?

Check the resistance between the amp ground and the chassis. If it's over .5 ohms, redo the ground wiring. Make sure you're grounding the wire to the bare metal of the chassis and not a painted part.

If wiring is in spec it seems to me a connection may be loose.

 

Not sure on the gauge..its decently think.

I have it ground at the seat bolt...maybe thats the problem. The thing is, thast the same spot I used to have it at and never had a problem. Ill check it out.

Oh yea..one other thing. The amp is running in mono mode (bridged)...if I plug both RCA cables into the stereo..the amp shuts off...if only the mono rca output is hooked up..it works...WTF is up with that?

 

ok i kno this sounds like a wierd question.. but im just trying to cover everything.. is the amp bridgeable? if not maybe thats why it doesnt work when u plug in the 2nd channel? or maybe like the guy on top said.. the amp is bad...

if all your wiring is correct.. i really dont know what else to tell you... make sure your fused power wire is of the correct guage, your remote turn on is hooked up to your amp, and its properly grounded to a bare metal surface.. and that you have good quality wires connected to everything (power cables, RCA cables, speaker wire)

 

yes its bridagable..it says right on it.

maybe ill try a different amp and see what happens..if it stays on or not

 

How many ohms is the the 12 inch speaker you are running now.

Is the amp you are using 2 ohm stable bridged or 4 ohm stable bridged.

The reason:

If the speaker you are using is a 4 ohm speaker then when you bridge your amp it only sees 2 ohms.

If you ran two 4 ohm speakers in series then you created a 8 ohm load so now the bridged amp sees half of this which is 4 ohms.

Thus if your amp is not 2 ohm stable bridged it will shut off.
The reason why when you shut it off it works again is because this basically resets the protection circuit in the amp. You should be able to do the same thing just by turning the stereo off and then back on.

Hope this helped.



[Modified by nsxxtreme, 8:14 PM 3/12/2002]

 

Well, I went out and bought a Fosgate Punch 150S amp..and same ******* ****

It worked for like 5 minutes..then the bass seemed to get quieter..then it stopped working. The light styas on..but doesnt make any noise. Restarting the car doesnt help either.

Could it be the voltage is dropping at the amp? It says it needs to be at least 10V..if its under that..would it stop working? And would the LED still be on?

 

Ok...heres some more weird ****...

I tried a new RCA cable, no luck
Tried a seperate remote tun on, no luck
Tried new speaker cables, no luck

I then tried to run the amp in normal mode (not bridged)...and get this...
When I hook the speaker to the left channel output...the LED is bright (normal)..but still no sound
If I hook up the right channel output..no LED at all..and still no sound
If its hooked up in bridged mode...the LED is on but dimmed.

What the hell!

 

I would take it to someone that knows what they are doing. You are doing something very wrong. From your info you have provided I can't tell what you are doing wrong.

If you are still able to start your car then more than likely you have enough voltage to run the amp.


[Modified by nsxxtreme, 3:41 PM 3/13/2002]

 

Well...I think I found the problem.

First of all...I checked the OHMs of the speaker..and it read 0.5!? WTF!
So Ii thought that was the problem..installed a new woofer...read around 4.0 OHMs...turn it on..and nothing!

So..I test the power voltage and it reads fine...around 14V w/ car on. So thats not it.

So then I ran a test on the RCA outputs on the stereo...and nothing!
Well, a couple of times it read around 2.3V..but mostly 0.0V.
I believe the specs on the output for my deck is 2V.

Piece of ****! Ii guess Ill be taking everything back since Im not about to dish out money on a new deck just to have a subwoofer.

 

Your first mistake was buying a Sony amp and your second mistake was buying an MTX sub.

 

Ok...scratch that.

I tried another stereo..same model as mine but out of my sisters car..and guess what..same ****! There also is no voltage from the RCAs on her deck either..wtf.
Im giving up.

EDIT: OK...it works. The problem? Tthe amp.
I tried yet another amp and it worked. So, I guess I blew 2 amps.
Im guessing since the speaker was bad and was at .5 OHMs, it friend the amps?


[Modified by HX_Guy, 9:22 PM 3/13/2002]

 

QUOTE:Your first mistake was buying a Sony amp and your second mistake was buying an MTX sub

hahahaha^

where are you buying your stuff from? Fry's or something where they let you return everything at will? that'd be pretty crazy if in fact there are 2 blown amps...
will your set up work w/ 1 sub? anyway at least you got it working.. what brand did you end up going w/..

 

Ive only been running 1 sub the whole time.

I dont get the question of where am I buying this stuff and that Sony and MTX are crap. There was nothing wrong with the Sony or Fosgate amps..the speaker broke (which does happen) which in turn broke the amps.

 

welll in my 8+ years of messing w/ cars.. i've never had that happen to me.. and you had 2 blown amps.. so i was just wondering where you got your stuff from... Sony amps really arent that good IMO.. I'm not knocking your stuff.. thats just my opinion.. sorry if i offended you... Fosgate makes alright amps.. so what amp and sub did you end up going w/? the same stuff.. but you just exchanged it for working equipment?

 

I used the same kind of sub, I had 2 of them..but only was using one of them...so I had a spare.

Right now Im using a small *** Jensen amp until I take the Fosgate back...but I might actually kep the Jensen. It doesnt hit very hard...but Im not looking to set records...just something to sound decent so I dont ahve so much treble and no bass.

 

A speaker being blown should not blow an amp. You must have repeatedly tried to power that speaker. Normally the protection circuit built in the amp would trip the the amp into shutting off. This is why you had to turn your car off and on to get it to turn back on. If it doesn't work the first time then doen't turn it back on unti l you find the problem. You should have checked everything the first time around. I can't believe you don't know what a blown speaker sounds like. Next time test all of your connections with a multimeter first. Live and learn I guess, expensive lesson though.

 

Hey, it kinda sounds like a prob i had for a while. I found out that i had my amp connected to a poor ground, and it was causing the amp to grond itself through the rca cable. I didn't figut out what was going on untill i killed my amp....