Jeep Wrangler Forum  

Go Back   Jeep Wrangler Forum > General Tech Forums > Communications and Electronics



Reply
 
Thread Tools Display Modes
Old 10-28-2009, 08:37 AM   #1
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default some help with my amp...

The other day I blew the 25 fuse on my amp, threw in a 40 and it was working fine, this morning on the way to work, halfway through godsmack, the sub just stopped working....i wasn't blasting it either, just moderate loudness, the fuse on the power line and on the amp look fine. I had the sub setting to a 6 out of 15, could that 40 be too big of a fuse? any ideas of whats going on? thanks guys and gals

__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-28-2009, 09:03 AM   #2
s3nt3nc3d
Jeeper
 
s3nt3nc3d's Avatar
 
Join Date: Oct 2009
Location: Piqua, OH
Posts: 196
Send a message via AIM to s3nt3nc3d
Default

If your amp was manufactured with the 25 and you put a 40 in there...1.) you masked the problem 2.) The circuitry in the amp may have only been able to carry 25 amps or less...you may have melted some internals or burned something up.

Did the amp just go into protection mode? If you blew the 25 amp fuse, you really should have replaced it with a 25...and if it happened again, you should have then had it looked at to determine what's shorting out. Putting in a higher fuse is a bad idea and can often times lead to stuff burning up/fires.

Also, are there any fuses inside the amp that could have blown? Or maybe fuses on or near the headunit? Good luck...hopefully the amp isn't toast.
s3nt3nc3d is offline   Reply With Quote
Old 10-28-2009, 09:28 AM   #3
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

mmm... well the 40 has only been in there for a day, i planned to stop at the hardware store after work to pick up a 25. i doubt its busted up, well i have my fingers crossed anyways. :/
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-28-2009, 05:18 PM   #4
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

its in protection mode...
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-28-2009, 06:16 PM   #5
baja
Hyperactive member

WF Supporting Member
 
baja's Avatar
 
Join Date: Oct 2009
Location: northwest iowa
Posts: 249
Default

check your ground,I had the same prob,went twice as heavy with ground wire than power and that fixed it.
baja is offline   Reply With Quote
Old 10-28-2009, 06:48 PM   #6
baja
Hyperactive member

WF Supporting Member
 
baja's Avatar
 
Join Date: Oct 2009
Location: northwest iowa
Posts: 249
Default ground

went twice the size for ground
Attached Thumbnails
Click image for larger version

Name:	DSC01584.jpg
Views:	4
Size:	86.9 KB
ID:	12411  
baja is offline   Reply With Quote
Old 10-28-2009, 07:35 PM   #7
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

mmm my ground is pretty snug and my ground wire is 8 guage i think? pretty beefy definitely the same size as yours baja. i just put in a 25 fuse and it still won't work. The led's will light up but thats it. since it was working earlier this afternoon i'm gonna say that something inside is melted.... for $12 the dealer will fix it and send it back to me within 2 weeks. i guess i'll be off to the post office in the morning.
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-28-2009, 09:44 PM   #8
baja
Hyperactive member

WF Supporting Member
 
baja's Avatar
 
Join Date: Oct 2009
Location: northwest iowa
Posts: 249
Default

going into protect mode usually indicates one or more mosfet output transistors has shorted.Thats out of the manual for my amp.
baja is offline   Reply With Quote
Old 10-28-2009, 10:53 PM   #9
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

mm i'm hoping they can just fix it up real quick and get it back to me. the music sounds okay right now, but i really need those low and deep wavelengths back.
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-29-2009, 11:52 AM   #10
Jaydogg25
Jeeper
 
Join Date: Jun 2009
Location: Columbus, Ohio
Posts: 78
Send a message via AIM to Jaydogg25
Default

like was posted above only put same fuse in never use larger thats asking for issues. there can be several issues goin on. and would need more information.

1) what's the RMS power of the amp?
2) what Ohm load is amp stable to?
3) what is the RMS of the Speaker(s)?
4) what Ohm load is speaker(s)? and how many voice coils?
5) are the sub(s) still good? take a ohm meter to them and see what they read.
6) make sure ground is to a clean, un painted metal surface and bolted solid (i prefer to use a factory bolt, or i drill a hole and use nut & bolt so i know it's solid) don't do the 2-3 screw in ground they suck.
7) do you have a fuse under hood by battery?

just bc a shop if fixin the amp doesn't mean that the problem your having will be fixed, could be something else going on here.
__________________
95 YJ, 4" suspension lift, 32's
Jaydogg25 is offline   Reply With Quote
Old 10-30-2009, 10:54 AM   #11
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

ok i've found this so far
NITRO BMW-481 (BMWX-481) <br>2-Channel 800W AMPLIFIER for the amp
Sony XS-L1237 12" 4-ohm subwoofer at Crutchfield.com for the sub

i do have a fuse under the hood, but its fine and the ground is clean. i'm not too sure what all thus RMS stuff means... i have a meter and can make measurements soon. with the amp... when i first blew the fuse the two blue led's would still light up when the reciever was turned on, just no music came out. once i realized it was the fuse i made the mistake of replacing the 25 with a 40. after a day when i was driving home the sub just stopped working. replaced the fuse and still nothing. when i turn on the reciever the led's still light up. just no sound. when i turn on the reciever the amp is in protection mode. where should i go from here?
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-30-2009, 11:52 AM   #12
Jaydogg25
Jeeper
 
Join Date: Jun 2009
Location: Columbus, Ohio
Posts: 78
Send a message via AIM to Jaydogg25
Default

RMS is the true power a amp puts out or a speaker can handle.. Max/Peak is a useless rating thats there for people who like to see big numbers.

looks like that amp does 200w rms @ 4ohm bridged. and the sub is rated @ 75-300 rms (which is a strange listing) but either way should be ok w/ it. just make sure sub isn't distorting. even though your w/in specs you can still blow a sub/amp.. distortion is the bigest killer of stereo equipment.

what i was making sure of was that you were not overpowering the sub. also that the load on the amp was correct. i have seen too many people just hook up any sub to any amp and not make sure they will work together.

**edit**
the reason i was goin to have you measure the ohm load of the sub was to make sure it's still correct @ 4ohm (or very close to that) bc if the sub is blown then you will blow up amp again when you hook it up.
__________________
95 YJ, 4" suspension lift, 32's
Jaydogg25 is offline   Reply With Quote
Old 10-30-2009, 11:21 PM   #13
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

aah, i thought the set up was within each components range when i bought them. its been running fine all summer since i put it in there. its just this week that i blew the fuse for the first time. right now the amp is out of the vehicle. i gotta wait till tuesday to get back at it. so i'll measure the ohm load, and if its around 4 then that's good, but where would i go next?
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-31-2009, 01:37 PM   #14
Jaydogg25
Jeeper
 
Join Date: Jun 2009
Location: Columbus, Ohio
Posts: 78
Send a message via AIM to Jaydogg25
Default

measure load of the speakers....bc if amp is getting fixed should be good..but if ohm load is like 2 or 0 on speaker and you hook it up again it will blow amp again. just things i do @ shop when checking ppl's systems out.
__________________
95 YJ, 4" suspension lift, 32's
Jaydogg25 is offline   Reply With Quote
Old 10-31-2009, 01:49 PM   #15
kdukes4
Jeeper
 
kdukes4's Avatar
 
Join Date: Apr 2008
Location: Maine
Posts: 475
Default

so check the speakers or sub? the amp just runs the sub, the speakers run off of the alpine reciever.
__________________
97 TJ 2.5L 33x1050 KM2's, crager soft 8's, Alpine CDA-7875 w/ 12" in homemade trunk sub box & 800W amp, 3" zj coil springs w/ Skyjacker Hydro 7000's, Baystate Front Bumper w/ Brush Guard & Winch Plate, Aftermarket Air Intake, Custom Magnaflow Cat Back Exhaust, POR15 under the tub
kdukes4 is offline   Reply With Quote
Old 10-31-2009, 03:22 PM   #16
s3nt3nc3d
Jeeper
 
s3nt3nc3d's Avatar
 
Join Date: Oct 2009
Location: Piqua, OH
Posts: 196
Send a message via AIM to s3nt3nc3d
Default

Quote:
Originally Posted by kdukes4 View Post
so check the speakers or sub? the amp just runs the sub, the speakers run off of the alpine reciever.
Subs are speakers too...check all speakers hooked up to the amp (ie the sub).
s3nt3nc3d is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -5. The time now is 09:28 AM.


Other Social Knowledge forum communities:
Cooking Forum - Sailing Forum - Early Retirement - Airstream Trailer - Aquarium Forum - Royal Forum - Book Forum - Volkswagen Touareg Forum - Jeep Wrangler Forum - Whitewater Kayaking & Rafting Forum - Fiberglass RV Forum - RV Forum - Truck Conversion - U2 Music Forum
Social Knowledge Networks
Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.3.0

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC