Battery going dead = H/K system working!!

2001 4.6 Vogue.

I have not used the car for a few days and then only to jump start my mates dead P38. My stereo system has not worked for past 4 weeks, well it works but no sound, suspect DSP amp. Went out to start car this morning for work, battery dead, jump started off the gaylander, off she goes to work. Turns on radio just in case???? and it bloody worked, all preset channels all still available?, however it only lasted for about 5 mins, then went muted/silent again. How can this be, will re-charge battery no prob but am now at a loss with the amp!! Any suggestions how and why it worked for a bit??? Cheers all:confused

Interesting one... Truth is I have no idea, I know alot about the wiring but very little about the DSP amp itself. Maybe time for a bit of creative diagnosis?

Try unplugging the amp completely and leaving it overnight, then plugging it back in the next day and see what happens.

Clarky130 said:

Interesting one... Truth is I have no idea, I know alot about the wiring but very little about the DSP amp itself. Maybe time for a bit of creative diagnosis?

Try unplugging the amp completely and leaving it overnight, then plugging it back in the next day and see what happens.

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It's driving me nuts, i would consider replacing some/all of the system but it's quality when it works!!, plus the factory sat- nav goes through it. I know it's not the best sat nav but i like to try and keep it original. And at £527 for new DSP amp not a cheap fix. Will try disconnecting amp overnight sometime soon, any thing worth a try. Cheers for your reply.

One thing that springs to mind - it may have some form of protection circuit that shuts off the output if it detects a short circuit. This is something found on pretty much all amps. I'm just wondering if corrosion or degradation is creating a low-impedance pathway on the output side that overheats the amp after a while, causing it to shut itself down? Other amps do likewise, and normally the only way to get them to reset is to remove power completely and then reconnect after a short period.

What may be worth trying is, after disconnecting, wait 10 mins or so and then reconnect, fire up and see if it comes back. If it does, keep the system running and feel if the amp is getting unduly warm - that might give us a clue.

Not very electronically minded sorry, but i think i get what you're saying. will have a look later when she comes home from work with it. Very bizarre as all this only occurred a few weeks ago, the same time as i changed spark plugs and leads!! things on these cars never cease to amaze me!

Maybe it's time to investigate a 'how-to' for replacing the troublesome DSP amp with aftermarket units... I already have some ideas how, just need to experiment. It may need to be done in conjunction with an aftermarket HU, though, or an attenuator with baluns to convert balanced into unbalanced at the other end...

Clarky130 said:

Maybe it's time to investigate a 'how-to' for replacing the troublesome DSP amp with aftermarket units... I already have some ideas how, just need to experiment. It may need to be done in conjunction with an aftermarket HU, though, or an attenuator with baluns to convert balanced into unbalanced at the other end...

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it would be great to be able to change the DSP amp with an aftermarket unit. Ridiculous price for new, and that is governing the price of second hand units. It seems that a disco2 unit will operate a couple of speakers for you, but no changer, sat nave etc. I hope you do come up with a suitable exchange unit..............

lizalandy said:

it would be great to be able to change the DSP amp with an aftermarket unit. Ridiculous price for new, and that is governing the price of second hand units. It seems that a disco2 unit will operate a couple of speakers for you, but no changer, sat nave etc. I hope you do come up with a suitable exchange unit..............

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Sat nav will complicate matters, but from what I understand of the RAVE diagrams, it seems it's only input into the DSP amp is for audio. That shouldn't be too hard to get around with a couple of audio relays.