Hi,
I'm a DIY novice and was wondering if any of you guru's could give me a few ideas. I have managed to install a new JVC KD-G615 stereo into my car. My mate offered me his old amp and sub, so I jumped at the chance to install my first sub.
So after getting all the cable and fuses etc. I had the sub working and everything was fine for a few days. However the fuse in the amp blew, and everytime I put a new fuse in it blows straight away.
I have tried looking online for the specifications of the amp but can't find any info. It's an Audio Gods AG 450 amp. Does anyone have info on what might be wrong? I have double checked that the amp is earthed etc, now I'm stumped. Maybe the amp is rooted?? But I thought I'd ask you guys first.
Any help or ideas would be greatly appriecated.
Cheers
Replies (8)
UKinstaller on 09/1/2006 09:03:36
if it blows immediately, you've either got a blown amp, or your power wire is touching bare metal somewhere. trace it down front to back and see if it's pinched and touching chassis.
-UK
swez on 09/1/2006 10:06:53
Agreed... this problem is usually associated with shorts, improper wiring of subs to amp or amp gain setting issues.
The fuse that is blowing... is this the main power line fuse or a fuse in the amp? Here's a short list of items to look at:
1. Main power wire is shorting to ground and blows main fuse
2. Main power wire at amp has tiny (hair) wires shorting to amp chassis
3. Remove sub wires from amp outputs (if amp turns on and no fuses blow now, you sub wiring, ohmic load and gain settings need to be looked at very carefully)
Item #3 is the easiest one to eliminate, but a test meter is most helpful for diagnostics. Here, it might be best to have a Pro Installer troubleshoot at this level.
Swez
Barbershark on 09/2/2006 06:48:38
Thanks for the advice guys, I will try and track it down first thing in the morning. It is the fuse in the amp that is blowing. The main fuse is fine, I had checked the main power and it seemed ok, but I'll have to look closer and see about the hair wires.
I grounded the amp, by attaching the earth cable to the metal brackets under the seat. I noticed that these brackets have some sort of coating on them, should I scrape the brackets back to clean metal with a wire brush... could this have anything to do with the fuse blowing?? Sorry I really am a novice.
I'll let you know how I go... thanks for the help so far :)
swez on 09/2/2006 09:59:15
Yep, clean, bare, shiney metal surface for grounds.
If the amp fuse is blowing, disconnect all your speakers and try it. If the fuse does not blow, your speakers are the likely culprit.
If the fuse blows with the speakers disconnected, the amp has internal damage and needs to be repaired or replaced. (Output transistors fried or power supply is damaged)
Swez
Barbershark on 09/14/2006 02:13:01
sorry for delay in reply... it seems as though the amp is screwed after all!!! :(
I can't decide if I want to try and fix it myself or just buy a replacement???
Thanks for all your help guys!!
swez on 09/15/2006 00:56:05
Tha amp may be "kaput", but you need to figure out why. If you replace the amp and do not correct the root cause, it may damage a new amp too.
swez
Barbershark on 09/17/2006 09:10:11
thanks swez, I hadn't thought about that.
Any tips on trackin the source. I opened the amp and it looked as though something in it had fried. There was a burnt spot at one of the connections (if that makes any sense)
I will have to try and get a photo of the amp on the posting ?
Cheers
swez on 09/17/2006 10:24:18
That burnt spot is telling a very important clue. This usually indicates that circuit/device was seeing too much current and may have flamed out. If you can remove the circuit board and flip it over, look for blown out spots in the conductor tracings. In most cases, this can be repaired and the amp will work again.
There are 2 main things that will fry an amp consistantly:
1. Power and ground wires were installed in reverse polarity (Rare, but it does happen)
2. Ohmic load the amp was seeing is/was too low for the amp to operate safely (Very common when speakers are wired up w/o adequate knowledge)
Item #1 will often fry an amp or blow fuses immediately. Item #2 is often more common and we often use an Ohmeter to measure the subs/speaker DC resistance.
Most good quality amps have output short/low ohms detection circuits and will shut the amp off or go into protect mode.
This amp, is it a 2 channel amp or a Class D type MONO sub amp?
swez
I'm a DIY novice and was wondering if any of you guru's could give me a few ideas. I have managed to install a new JVC KD-G615 stereo into my car. My mate offered me his old amp and sub, so I jumped at the chance to install my first sub.
So after getting all the cable and fuses etc. I had the sub working and everything was fine for a few days. However the fuse in the amp blew, and everytime I put a new fuse in it blows straight away.
I have tried looking online for the specifications of the amp but can't find any info. It's an Audio Gods AG 450 amp. Does anyone have info on what might be wrong? I have double checked that the amp is earthed etc, now I'm stumped. Maybe the amp is rooted?? But I thought I'd ask you guys first.
Any help or ideas would be greatly appriecated.
Cheers
Replies (8)
UKinstaller on 09/1/2006 09:03:36
if it blows immediately, you've either got a blown amp, or your power wire is touching bare metal somewhere. trace it down front to back and see if it's pinched and touching chassis.
-UK
swez on 09/1/2006 10:06:53
Agreed... this problem is usually associated with shorts, improper wiring of subs to amp or amp gain setting issues.
The fuse that is blowing... is this the main power line fuse or a fuse in the amp? Here's a short list of items to look at:
1. Main power wire is shorting to ground and blows main fuse
2. Main power wire at amp has tiny (hair) wires shorting to amp chassis
3. Remove sub wires from amp outputs (if amp turns on and no fuses blow now, you sub wiring, ohmic load and gain settings need to be looked at very carefully)
Item #3 is the easiest one to eliminate, but a test meter is most helpful for diagnostics. Here, it might be best to have a Pro Installer troubleshoot at this level.
Swez
Barbershark on 09/2/2006 06:48:38
Thanks for the advice guys, I will try and track it down first thing in the morning. It is the fuse in the amp that is blowing. The main fuse is fine, I had checked the main power and it seemed ok, but I'll have to look closer and see about the hair wires.
I grounded the amp, by attaching the earth cable to the metal brackets under the seat. I noticed that these brackets have some sort of coating on them, should I scrape the brackets back to clean metal with a wire brush... could this have anything to do with the fuse blowing?? Sorry I really am a novice.
I'll let you know how I go... thanks for the help so far :)
swez on 09/2/2006 09:59:15
Yep, clean, bare, shiney metal surface for grounds.
If the amp fuse is blowing, disconnect all your speakers and try it. If the fuse does not blow, your speakers are the likely culprit.
If the fuse blows with the speakers disconnected, the amp has internal damage and needs to be repaired or replaced. (Output transistors fried or power supply is damaged)
Swez
Barbershark on 09/14/2006 02:13:01
sorry for delay in reply... it seems as though the amp is screwed after all!!! :(
I can't decide if I want to try and fix it myself or just buy a replacement???
Thanks for all your help guys!!
swez on 09/15/2006 00:56:05
Tha amp may be "kaput", but you need to figure out why. If you replace the amp and do not correct the root cause, it may damage a new amp too.
swez
Barbershark on 09/17/2006 09:10:11
thanks swez, I hadn't thought about that.
Any tips on trackin the source. I opened the amp and it looked as though something in it had fried. There was a burnt spot at one of the connections (if that makes any sense)
I will have to try and get a photo of the amp on the posting ?
Cheers
swez on 09/17/2006 10:24:18
That burnt spot is telling a very important clue. This usually indicates that circuit/device was seeing too much current and may have flamed out. If you can remove the circuit board and flip it over, look for blown out spots in the conductor tracings. In most cases, this can be repaired and the amp will work again.
There are 2 main things that will fry an amp consistantly:
1. Power and ground wires were installed in reverse polarity (Rare, but it does happen)
2. Ohmic load the amp was seeing is/was too low for the amp to operate safely (Very common when speakers are wired up w/o adequate knowledge)
Item #1 will often fry an amp or blow fuses immediately. Item #2 is often more common and we often use an Ohmeter to measure the subs/speaker DC resistance.
Most good quality amps have output short/low ohms detection circuits and will shut the amp off or go into protect mode.
This amp, is it a 2 channel amp or a Class D type MONO sub amp?
swez
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