The title says it all. In a nutshell a friend and I had a stereo installed in a Yukon Denali XL. The amplifiers that keep burning up are Directed Audio 2400Ds. There are a total of 3 of these amplifiers powering 3 JL Audio 12W7s. Two of the amps have been sent back to Directed and replaced. Those amps have now blown again within 6 months after being replaced.
I am currently blaming the problem on the electrical system so I will explain this starting from the battery on back.
POWER SYSTEM
-Optimus Battery connected to 160amp alternator.
-1/0 AWG wire running to the rear of the car.
-200 amp Wafer fuse block
-1/0 AWG running from block to second battery power terminal
-1/0 AWG leaving second battery to third battery power terminal
-1/0 AWG leaving third battery into high current relay that is activated by head unit remote
-1/0 AWG leaving relay into Alumpro 15 farad cap
-dual 4 AWG leaving CAP into distribution block
-Three 4 AWG powers leaving block into 3 separate 200A fuse holders.
-All powers then run to amps
GROUND SYSTEM (starting from grounded point in rear)
-2 AWG ground leaving chassis ground point
-2 AWG hits distribution block
-From distribution block three 4 AWG grounds run to each amplifier
-Also from distribution block 2 AWG ground runs to ground terminal on third battery.
-2 AWG leaving third battery into second battery ground.
Judging by the system listed above it seems to me that for one the 200A fuses are too high. Directed recommends 160A fuses. Also the there is a difference between the power wire AWG and the ground wire AWG. Both AWGs should be the same.
Does anyone agree that a combination of the ground wire gauge being smaller than the power wire gauge and the higher AMP fuse ratings could cause this type of amp failure?
BTW both amps ended there existence via an entire channels output stage letting the smoke out. See pic
I am currently blaming the problem on the electrical system so I will explain this starting from the battery on back.
POWER SYSTEM
-Optimus Battery connected to 160amp alternator.
-1/0 AWG wire running to the rear of the car.
-200 amp Wafer fuse block
-1/0 AWG running from block to second battery power terminal
-1/0 AWG leaving second battery to third battery power terminal
-1/0 AWG leaving third battery into high current relay that is activated by head unit remote
-1/0 AWG leaving relay into Alumpro 15 farad cap
-dual 4 AWG leaving CAP into distribution block
-Three 4 AWG powers leaving block into 3 separate 200A fuse holders.
-All powers then run to amps
GROUND SYSTEM (starting from grounded point in rear)
-2 AWG ground leaving chassis ground point
-2 AWG hits distribution block
-From distribution block three 4 AWG grounds run to each amplifier
-Also from distribution block 2 AWG ground runs to ground terminal on third battery.
-2 AWG leaving third battery into second battery ground.
Judging by the system listed above it seems to me that for one the 200A fuses are too high. Directed recommends 160A fuses. Also the there is a difference between the power wire AWG and the ground wire AWG. Both AWGs should be the same.
Does anyone agree that a combination of the ground wire gauge being smaller than the power wire gauge and the higher AMP fuse ratings could cause this type of amp failure?
BTW both amps ended there existence via an entire channels output stage letting the smoke out. See pic
Attachments
That's a very complicated wiring scheme, why do you have it like that?
All you need is 1/0 leaving the battery, running through an ANL fuse holder within a couple of feet, run through an isolator to both of the batteries in the back. Then from the batteries to the cap, to the distro, and then to the amps. I don't understand why you have a relay cutting the cap out of the circuit, your cap has to instantly recharge every time you turn the key to ACC (your batteries are experiencing a dead short for a second until the cap fills up every time you turn the key to ACC after the car has been off long enough for the cap to discharge). I would take the relay out, do you have a fuse by the battery in the front? If not then you need one to prevent a fire in case of a short.
The fuse is not causing a problem, the fuse is ONLY there to cut off the current flow if there's a short, it needs to be sized according to the wire you're using, it has practically nothing to do with the amps you're using (apart from the fact that it needs to be large enough that it doesn't blow under normal conditions). The grounds also do not need to be the same size as the power, all this means is you have less resistance in your ground circuit than in your + circuit, which is nothing but good.
The amps are blowing for another reason. I've never been a fan of Directed but they shouldn't be blowing THIS much. Are you running them below their rated impedance? Are you blocking any built in fans? Are they encased in some pretty amp rack and not allowed to vent off their heat? How are the gains set?
All you need is 1/0 leaving the battery, running through an ANL fuse holder within a couple of feet, run through an isolator to both of the batteries in the back. Then from the batteries to the cap, to the distro, and then to the amps. I don't understand why you have a relay cutting the cap out of the circuit, your cap has to instantly recharge every time you turn the key to ACC (your batteries are experiencing a dead short for a second until the cap fills up every time you turn the key to ACC after the car has been off long enough for the cap to discharge). I would take the relay out, do you have a fuse by the battery in the front? If not then you need one to prevent a fire in case of a short.
The fuse is not causing a problem, the fuse is ONLY there to cut off the current flow if there's a short, it needs to be sized according to the wire you're using, it has practically nothing to do with the amps you're using (apart from the fact that it needs to be large enough that it doesn't blow under normal conditions). The grounds also do not need to be the same size as the power, all this means is you have less resistance in your ground circuit than in your + circuit, which is nothing but good.
The amps are blowing for another reason. I've never been a fan of Directed but they shouldn't be blowing THIS much. Are you running them below their rated impedance? Are you blocking any built in fans? Are they encased in some pretty amp rack and not allowed to vent off their heat? How are the gains set?
Personally I would not have installed the relay either but it was done by a certified installer. This is my question though; wouldn't the batteries in the rear end up continually powering the caps? With the Alumpro cap, could this drain the battery over time?
To answer a few of your questions:
- The 2400D's are mono amps and rated at 2400 watts into a 2 Ohm load. The 12W7s have a single 3 ohm VC and thus would put the amp at lets say 1600 watts give or take.
- The amps do not have built in fans. They are mounted within a closed amp rack but there are multiple fans both sucking air in and blowing air out.
- I'll get back to you about the gains.
Anyone needs pictures let me know.
know.
To answer a few of your questions:
- The 2400D's are mono amps and rated at 2400 watts into a 2 Ohm load. The 12W7s have a single 3 ohm VC and thus would put the amp at lets say 1600 watts give or take.
- The amps do not have built in fans. They are mounted within a closed amp rack but there are multiple fans both sucking air in and blowing air out.
- I'll get back to you about the gains.
Anyone needs pictures let me know.
know.
i can see why they put a relay under the hood to cut the power to the amps, that cap is huge. besides are the amps on there own charging system? if not, they should be, then you could cut out the relay. there should be a fuse under the hood after any batteries and if there are any batteries in back there should be a fuse before the batt's and after the cap right before tha block to the amps. this should cut out any possible fire hazards.
as for the amps, imho, i would start looking at others at maybe at a different shop. planet audio makes some sick amps, so does memphis and kicker. i would also go to another shop and have them inspect the setup, if they look at it and give a big WTF about the install then go back and demand they take it all out and give you your money back. if they dont, talk to a lawyer about sueing them, becouse they could have/be putting you and anyone else in danger with the setup. oh and lots of pix too... but thats just my 2 cents...
as for the amps, imho, i would start looking at others at maybe at a different shop. planet audio makes some sick amps, so does memphis and kicker. i would also go to another shop and have them inspect the setup, if they look at it and give a big WTF about the install then go back and demand they take it all out and give you your money back. if they dont, talk to a lawyer about sueing them, becouse they could have/be putting you and anyone else in danger with the setup. oh and lots of pix too... but thats just my 2 cents...
We have already purchased new amplifiers. That is the reason we are trying to find any faults before the new ones get installed. We have decided to go with three JL Audio 1000/1s.
I have done multiple car installs and am aware that there should be a fuse in the engine compartment as close to the battery as possible. This is the first time I have done actually taken everything apart and seen how it was wired. I couldn't believe that there was no fuse put near the engine battery as this is a very basic rule.
What do you mean by there own charging system?
I have done multiple car installs and am aware that there should be a fuse in the engine compartment as close to the battery as possible. This is the first time I have done actually taken everything apart and seen how it was wired. I couldn't believe that there was no fuse put near the engine battery as this is a very basic rule.
What do you mean by there own charging system?
Killjoy99 said:
Depends on the cap, it will burn off some of its stored power over time, if you leave it disconnected from a power source for several hours it will probably go dead, then when you turn the key to ACC you have a surge of power from the batts trying to recharge it again. Once it's charged all the batteries would have to supply is a very very small amount of current to make up for what's being burned off internally. Caps really can't hold that much energy, at all, it doesn't take much for them to go dead and need to be recharged, but at the same time it doesn't take much to keep them charged. With 3 batteries you definitely wouldn't have to worry about the little cap sucking the electrical system dry overnight, maybe after a few years though.
From the photo, it's difficult to tell which transistors actually failed. Can you post an overall photo of the board and two more, each showing 1/2 of the board?
It's rare that outputs fail as those you've shown. It's typically power supply transistors that make a mess like that. If the outputs failed, you can be confident that the power connections in the vehicle are not the cause.
Powering the cap via a solenoid is going to be tough on the solenoids contacts if the cap is significantly discharged when the solenoid is off. In time, I'd expect that the contacts would increase in resistance and may cause you to lose significant voltage when high current is drawn through the solenoid. You can check the voltage drop across the large terminals of the solenoid with a voltmeter. Measure the voltage when the system is being run at full power. At low current, the voltage drop will be near zero volts.
If the cap has a remote terminal, there should be negligible current draw (when there is no remote voltage present) and the solenoid can be eliminated (if it's only there because they were concerned that the cap would drain the batteries).
The fuses, in my opinion are a huge problem. It's possible that the proper fuses could have protected the amp. You would have to draw nearly 1000 amps through a 200 amp fuse for it to blow quickly enough to protect the amp (FETs blow very quickly when things go wrong). I would suggest a 125 amp fuse. From the specs I found on the current version of the amp (D2400), it's 1200 watts RMS. It's unlikely that you'll blow a 125 amp fuse with a 1200 watt class D amp.
You mentioned that the same two amps failed. This may mean that something is wrong with the speakers or the wiring. I've seen speakers that had long lead-in wires and when the system was driven hard, the wires would short. Many manufacturers use insulated lead-in wire now but it's something you should check.
Check your wiring going to the woofers. Look at it very closely. I've seen speaker wire short between conductors. Sometimes the short is intermittant so it may not show up with a meter. It may take significant voltage to cause the arc between conductors. If this is happening, you can generally see a tiny black spot in the insulation between the conductors.
Having different sized power and grounds isn't really a problem in your situation but... any added resistance increases the time it takes for a fuse to blow. Even tens of milliohms may make the difference between the amp surviving and failing catastrophically.
It's rare that outputs fail as those you've shown. It's typically power supply transistors that make a mess like that. If the outputs failed, you can be confident that the power connections in the vehicle are not the cause.
Powering the cap via a solenoid is going to be tough on the solenoids contacts if the cap is significantly discharged when the solenoid is off. In time, I'd expect that the contacts would increase in resistance and may cause you to lose significant voltage when high current is drawn through the solenoid. You can check the voltage drop across the large terminals of the solenoid with a voltmeter. Measure the voltage when the system is being run at full power. At low current, the voltage drop will be near zero volts.
If the cap has a remote terminal, there should be negligible current draw (when there is no remote voltage present) and the solenoid can be eliminated (if it's only there because they were concerned that the cap would drain the batteries).
The fuses, in my opinion are a huge problem. It's possible that the proper fuses could have protected the amp. You would have to draw nearly 1000 amps through a 200 amp fuse for it to blow quickly enough to protect the amp (FETs blow very quickly when things go wrong). I would suggest a 125 amp fuse. From the specs I found on the current version of the amp (D2400), it's 1200 watts RMS. It's unlikely that you'll blow a 125 amp fuse with a 1200 watt class D amp.
You mentioned that the same two amps failed. This may mean that something is wrong with the speakers or the wiring. I've seen speakers that had long lead-in wires and when the system was driven hard, the wires would short. Many manufacturers use insulated lead-in wire now but it's something you should check.
Check your wiring going to the woofers. Look at it very closely. I've seen speaker wire short between conductors. Sometimes the short is intermittant so it may not show up with a meter. It may take significant voltage to cause the arc between conductors. If this is happening, you can generally see a tiny black spot in the insulation between the conductors.
Having different sized power and grounds isn't really a problem in your situation but... any added resistance increases the time it takes for a fuse to blow. Even tens of milliohms may make the difference between the amp surviving and failing catastrophically.
Killjoy99 said:
HAH, well now you see why "certified installer" doesn't mean anything, some lessons have to be learned the hard way. It's extremely bad practice to not use a fuse by the battery. Every wire that leaves the batt's + terminal should be fused, if it's not then there's a fire hazard, especially with such a large wire running such a large distance. I can't even count the number of threads I've read on various forums where people are complaining about how their car burned to the ground for no reason, come to find out it's because their power cable shorted out and they had no fuse.
I would find a new shop, immediately.
what i mean is a separate alternator and batteries for just the amps or the whole sound system.
this would isolate the stereo from the rest of the vehicle. that way you dont have those big amps on the vehicles electrical system, so one could play said stereo with out the truck running and not having to worry about the amps or anything else draining the batteries if your ride sits for a few days if something else is wrong, not only that but it does suck when you are cruising down the street and a hella-heavey bass line hits and your lights dim and kill the engine. those electronic engine managment systems in vehicles these days use a lot of juice too...
The failed FETs in the picture are in the power supply. The 'outputs' are on the other end of the amplifier. You need to check them with a multimeter set to 'diode check' or ohms to determine if any have failed. If you find a transistor that reads zero ohms (or near zreo ohms) between any 2 of its 3 terminals, it's defective. If any of the transistors in the audio section have failed, the power distribution is not the problem and you should check anything/everything connected to the output of the amplifier. If there are no defective transistors in the output section, the amplifier's switching power supply may have a weak point in its design.
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