I have a tricky one for you guys

[JeremyC]

Ok heres what happened. I was driving along and I hit a medium sized bump in the road and my sub cut out. At the same time it cut out I heard a thud like something in my trunk just hit something. Figured it wan't anything to big, so I shut off my deck and restarted it to see if the amp went into protection and needed reset. Of coarse the sub didn't come back on, so I left the volume really low and drove the rest of the way to work.

Well a few min later I hit another bump, and the sub is back, next bump and it is gone again???

So I pull over and move what few wires I can get to and find nothing. I figured it was my power or ground for my sub amp comming loose and I would fix it later. (both my 300/2 were still playing fine)

Well I get home and I strip the entire car. I can not for the life of me find the cause. All conections for power and ground are perfect. But the problem is still comming and going as before. But I can not for the life of me "make it do it myself" I shook every wie in that car, and I can not get it to act up myself.

So I moved on to checking the speaker and amp. The speaker is metering at 3 ohms (dead on for a W7), and again all conections are rock solid. The amp isn't giving any protection, low ohms, or other error lights, and all conections on it are tight. Even when the sub shuts off I am not getting any error lights on the amp. Thats one of the reasons I started with the power side first.

Since I couldn't find a problem there I decided to get it to fail and them move the cone to see if I had an open inside of the sub. Of coarse that didn't make a diffrence either.

Honestly I can't say I have narowed the cause down much at all. One sec it will do it at a medium volume, the next I can crank it for a few min, and then hit a bump while I am driving and off it goes.

The only thing I did notice was that when the amp powers on it flashes the low ohm, and overheat lights. They come on for a sec, then all lights go out, then the power light comes back on, along with sound from the sub. The 300/2 don't follow this same power on seq. They go strait to green power light, followed by volume. I figured this was normal OP for a class D, but I wanted to ask to make sure.

I still have it pulled apart, so I will mess with it more tommorow, but I would like a better idea where to start, or if you think of something I might have missed let me know.

[MrSo0h0o]

maybe the wiring at the posts inside the box on the sub? or did u try that already? is the wire straight to the sub or did u use a terminal cup? if its a terminal cup, maybe the wiring at that?

sorry cant be of more help, just felt i could throw out any ideas

[smoker]

sounds like it may be internal in the amp...we wired in a 500/1 one time that gave us some problems after about a week or 2 of use and wound up having to swap it for another and that fixed it...

[Justin from Detroit1]

Check the RCA's on the back of the HU.

[JeremyC]

Wires are strait thru, and yes the conection is still good. It shot right at 3 ohm which is about perfect given my setup.

Ok Justin, were are you going with this. I was going to check them anyways, but I am curious what pointed you in that direction??? UUUHHHH I think I just answered my own question. But go ahead and tell me anyways.

[Ryan from Ohio]

I know on some RCAs they dont grip the male's very well on the head unit.

I bought a set of cheapies to run to that 990.1D I had and I ended up tweaking them a bit so you had to 'push" them on with a bit of force. If I would of put them on how theyw ere they could potentialy work themselves loose or off...

Thats probably what hes thinking, and I agree. Its a possibility...

Also like smoker said, could be an internal amp problem. If everything is rigid mounted you may have jared something loose while driving. Like mounting your amp to the box is a no no for that reason. I know your car is tuned with a special suspension which could ride rough... maybe its mimicing the same principle as mounting the amp to the box?

dunno but I need to stop babling

[Chris from Washington]

I was going to say maybe something in the amp too. bad solder joint perhaps?

Start with the easy stuff (RCA's), then move on to the amp.

[Justin from Detroit1]

Like Ryan said. One of the RCA's could be ALMOST disconnected, and each bump makes it either abrely make contact, or lose contact slightly. It's worth a shot.

[jonnyb]

thats an easy solution:

stop driving over bumps!


if every connection is secure, its probably some internal problem with the amp.

[GlassWolf]

cheap RCAs also leave the connector's metal contact surface exposed, so the connectors can ground out to the chassis when they touch metal behind the deck when the deck is shoved into the dash.