I hate to add yet another post, but I cannot find a previous post with the same problem I'm having. My amp is spazzin on me. A couple of hours ago it just started cutting out and then the subs just started going thud thud thud thud thud thud thud thud thud...The amp is switching on over and over again. I can hear the switch coming on over and over again as it goes thud thud thud thud thud thud. I had a problem out of it a few months ago while under warranty and they did some soldering. I was so happy to finally be getting it out of the shop (they really only looked into it after I called Kenwood them) that I did not ask specifically what they did. But it's out of warranty and the 90 day repair warranty so I'm thinking of looking into it myself to see if anything loose is readily visible. Could it be the receiver, even though the receiver looks to be working just fine? If not what in blazes is wrong with my friggin amp?

BTW: Kenwood KAC-719 amp, MTX blue thunder pair of subs, and the head is Kenwood KRC-207S

 

Check your wirring connection from amp to speaker and gain level

 

Assuming there is nothing wrong with your amp internally, there are really only two things that could possibly go wrong. You have the remote running from the stereo to the amp, right? Initially I thought the remote could be too weak not allowing the amp to turn on. But if it turns on in the first place and then shuts off then this is not the problem. Usually it is better to run the remote from the fuse box when hooking up a high-powered amp, but in your case the head unit should be fine. My other question is is your head unit cutting out too? Since you didnt say ill assume no. So you are most likely looking at a bad ground from your amp to your car floor. Take a look and if the connection looks shady then unbolt the wire from the floor and sand down where it touches the metal to ensure a good connection. Sub hookups are not rocket-science. If your shop was not able to fix it then I encourage you to go elsewhere.

 

Well I've had this amp for about a year now. It messed up a like a couple of months ago. I took it to an authorized Kenwood shop and they fixed it. They did some soldering. That's all I found out (Have I written this in another post somewhere??) Anywho I have a 10 guage amp wire and 10 guage ground wire. I would like a longer ground wire that what came with the kit. I have 10 ft of 8 guage. Crutchfield says to use the same guage as is your power wire, though. Should I follow this instruction? I'm guessing that the ground wire should be relatively short, right? How short? I want it longer than 3 ft like at least 4 ft. THe short wire could be why the ground connection is sucky, if that is the case. That may be what the guys at the service center soldered. Alas, tell me what you can.

 

yep probably a bad ground or something else is grounding your amp out. follow all of you connections and see if something is touching

 

Well the ground is good and it's still doing it. It actually stopped for a while when I got back into the car after it did it the first time but it started up again. I thought it was a heat thing until it did it first time I drove Sunday morning. I opened it up to see if I could see anything loose and I see some white putty goop on two of what look like a capacitor. I was tried to find a capacitance but the goop is in the way. The goop goes from one cap to some ring with a copper coil around it. What's that? Some kind of inductor? I don't know if the repair people may have put that goop stuff on or if that is the way it came. Wish I had looked in first. Anywho, I am now clueless. It's within 90 days of the repair so it's going back to the repair people. I hope they don't try to keep it forever like they did last time, putting in on the shelf or something. Chumps think they won't have to give priority for non-HiFi audiophile crap. We'll see.

Your thoughts are appreciated. Thanks for all the replies thus far. Oh yeah, is it bad to mount the amp on top of the sub box? I've seen this done with a lot of systems. What of the integrated amps and subs? They're subjected to vibrations too. They're okay with it. I have mounted mine on a 2-sub rectangular box. I will check the remote switch from the radio to see that the signal is in fact not coming on and off.

 

Okay the voltage on the remote wire is 11.56V pretty steady. Does this sound about right. I measured with the engine off with the radio on. Something is definitely up with the amp, then, right?

 

You should take the amp out of your car and try hooking it up in a friends car with a system. If the amp works then you could have to re-wire everything in your car. If it still doesnt work you might have to cough up the money for a repair or try to get rid of it while it still semi-works and buy something else.

If you ask a professional your question they will tell you that yes the vibrations are bad and its not a good idea. But ive done it in the past where space was an issue. Even with the vibrations of 2 w3's bein pushed by 1200w it was fine.

 

It is also possible that the "thud" is a turn off noise. When you are turning on the stereo, does just the amp kick on and off? Or the whole stereo? Could be that battery voltage is dropping when you turn the amp on, and the amp shuts off. Then when the alternator kicks on and recharges the battery lightly the stereo kicks back on. Only to cause the same surge again, followed by shutting of again. My headunit is great for shutting down before the battery dies. It shuts off at about 11 volts and the battery still has enough juice to start the car. Then the alternator can recharge the battery.

In summary check to see if the battery and alternator are in good shape. After rechecking the power/ground wires. It is always safe to use larger than the minimum recommended gauge power and ground wires. And 10 gauge is a bit on the small side for a power wire for an amp.

 

This is kinda dated but I'd appreciated if you can help me too. I have the "thud" problem as well. I hear 2 "thud" noises from my sub everytime I turn on my head unit. My setup is like so: Bose HU with a converter connected to a amp. I have 95 gle by the way.

I got it installed at Al n Eds and they told me its because of the setup. He said the noise will go away if I get myself a new HU and run RCA cables. Is he right on this?

 

I don't know if it's the RCA converters or not. But if it's only when you turn it on you could get a small diode and cap to delay the amp turn on. Look in the faq's section. If the directions aren't there repost and I will find a couple links that hvae the info.

 

I don't know if it's the RCA converters or not. But if it's only when you turn it on you could get a small diode and cap to delay the amp turn on. Look in the faq's section. If the directions aren't there repost and I will find a couple links that have the info.

 

You need a delay on the remote turn on for the amp.

 

The longer the ground wire, the worse the connection. You should have as short of a ground as possible, under 24in if possible.

That white goop on the caps inside the amp is a heat conductive grease.

To test and see if you have a bad remote going to the amp, disconnect the remote wire and splice a small lenth of remote wire from the 12V+ of the amp to the remote input of the amp. This will keep your amp on all the time via a direct 12V connection from the battery. If your on/off problem goes away, then it is a problem with the remote. If it's still there, time for a new amp, and not a Kenwood. Try buying something better than that. You should be able to get a Rockfor 450S for under $300 at you local audio shop.

 

Okay just to let everyone know I took the amp back a couple of months ago and it was indeed the same problem for which I had taken it back before. The work they did was listed as welding of the PC board. I hope the rest of my kenwood stuff (HU,Changer,4speakers) doesn't start acting up. I hate the kenwood service center for my location. They are crooks. I wish I had never bought anything kenwood. If this amp screws up again I am going to send it somewhere else and just pay for the shipping myself. Or I may just go for the Rockford Fosgate since the Kenwood has been out of warranty since like April.