Sub amp overheating

zerosk8er

i have an mtx tc2002 hooked up to a rockford fosgate 10" p2
200 watts rms 400 peak
thats exactly the power rating of the driver
i have the amped bridged and the driver is 4 ohms according to the manual as long as its 4 ohms you can bridge it
i had 8 gauge wiring but the amp started to overheat so i switched it for 4 gauge
but the problem is not gone i will be listening to music with the sub at a moderate level (i'm not one of those people that you can hear coming from a mile away) for about half an hour to an hour i would say, and all of a sudden the amp will shut off, then after about half a minute it will turn on again then after about 5 minutes it will turn off again and that cycle continues.
i noticed that the amp gets so how that when i touch it it practically burns my fingers off!!
is this an amp problem? does the gauge of the wire going from the amp to the sub matter?(i have 12 gauge)
would a fan fix this? if so can someone recommend one?
thanks
-Alex

kimota

Hello

I have a Rockford Fosgate amp the P450.2 also bridged using two 10" 4 ohm Polk woofers and experienced almost the same issue. Simply adding a cooling fan resolved the issue, I got mine from this link at Sound domain.

I have my amps mounted to the back of my sub box, so the amps are sandwiched between my rear seats and sub box. After adding just 1 Stinger fan near my sub amp I no longer experience shutdowns not even on the hottest days.

Hope this helps

zerosk8er

how did you hook it up? did you just connect it directly to the same power cable going to the amp? and then to the same ground cable to the body?
and how is it mounted? did you have to sort of custom make a bracket?
thanks a bunch!
-Alex

kimota

I tapped the power from my rear cigarette lighter (mine is switched with the ignition) to power the fan, using the same ground point as amp. Although I have seen people run power and ground to the body as you mentioned.

I used velcro and screwed the fan to my back of my rear seat. The rear seat is is covered by a thin plastic pannel thats why I also put velcro on the back of fan to make it more secure.

I also added a on/off switch in the cabin of car for the fan for cooler days when I dont need the fan running.

zerosk8er

awesome thanks
i'm going to have to run it power to ground since i dont have a cigarette lighter back there but i like the switch idea
thanks alot though
out i go to get a fan
-Alex

Robd

Alex maybe I can help, without the noisy fan, I have had just about all problems, in car audio ( I am the mile away guy)...
sounds like you need better ground, the ground is = or more important than the power, is the ground on bare shiny steel (all paint removed), this alone would make your amp overheat seen it too many times, simple fix, otherwise it is arcing though a paint (high resistance, the amp will get very hot).
How long is the ground from the amp? Keep it as short as possible, and make shure you are using a large surface area ring terminal. This usually will solve your problem, you do not have enough of a load on that amp to overheat, that is why I say you do have an issue and the fan will keep it cool but does not fix the problem, (it will only mask the problem).
Should also ask is the listening with the car running? if you are running your system for 1/2-1 hour without the car running that would do it aswell, as your battery drains the voltage drops, and the current rises, that will aswell make your amp get smokin hot, if it does it with the car running different story.
how many amps are ya running aswell? I would need more car system info, if you are running 2-3 amps on a civic with a stock 60 amp alternator with a current draw of 90-100 amps, on a 60 amp alternator, as you can see the math don't add up, you will kill your electrical system, (this is an example) only because I don't know wether you are running deck power or an additional amp for mids/hi's.
Hope this helps.

Deadof_knight

When bridged the amp is going to run hotter every amp I own runns warmer in bridged or mono, however try raising the amp up off of the mounting plate slightly to allow air underneath as well,,,,,, just my 2 cents

zerosk8er

i pretty much always have the car running, its a 98 vw golf i dont have an amp going to anything but the sub the battery is new but not the alternator but im pretty sure its an 80 or 90 amp one since thats what they usually come with
the ground wire is 2 or 3 feet long with a big loop thingy at the end, however i had not shaved the paint off so i will do that is the wire too long? i was told it would be fine with stock alternator, i know that capacitors are supposed to help from straining the electrical system of the car would it help/is it worth it? i did hook up a fan anyways with a switch so i can shut it off from the driver seat, are there thermometers out there that i could place on the amp with a screen wired all the way to the drivers seat? because that would just put me at ease... the amp is already about half an inch off the ground leaving room for air circulation would raising it more make a difference?
thanks
-Alex

dudeinaroom

cut that ground down to 18". Scrape the paint, it you can go to your local auto parts store and get a wire wheel that you can throw in a drill to remove the paint. Try to use a bolt that goes down into a nice heavy piece of steel, not just a body panel. Make sure the bolt is good and tight to the terminal, then cover the whole thing with silicone to help slow oxidation.

zerosk8er

i scraped the paint away and already i notice a difference it didnt shut off in half an hour of driving around and i was pushing it more than usual and i kept the fan off...it did still get pretty hot but im pretty sure that it got to a point where it wouldnt get any hotter, just because i want to be on the safe site i got another fan and i'm going to wire it up so air gets all around the amp, i mean the cooler the better right? although i have herd that too cool is also bad which is why i have a switch and want a temperature gauge... any one know where i can get a temperature gauge??? i will cut the wire down although i dont know if i can get it down to 18"...
and no one answered my question about the capacitor... is it worth it? considering my car is old...
any other tips and tricks will be appreciated, thanks so much to everyone that has already helped out u guys rock
-Alex

dudeinaroom

You don't need a cap, just replace the Alternator to battery wire, replace the engine to chassis ground wire, and the battery to chassis ground wire with thicker ones.

Robd

All the advice from Dudeinaroom is all good, replacing the bat ground/alt cables is usually done with multiple amps, but new heavy guage cable is always a good idea ( if you could afford it or plan on adding more power, or if cable ends are oxidized, consider this your next step), the cap is good but only really required whith 500-1000 watts (1 farad per thousand watts), re cable your car would be more beneficial.
Odds are just repairing the paint/ground issue should solve all your issues,
as far as temp guage, Dakota Digital has what you are looking for, ( again depends on budget), as well a amp can never be too cool, ( unless your freezing it, all electronics run better cooler.
Good luck