bronto

Current situation:

New Blaupunkt head unit, built in amp
Blaupunkt 5" & 1.5" component speakers in the rear, directly wired to head unit
PO Installed door speakers, connected to small PO installed Sony amp under passenger seat.
Z-Box enclosure with 8" sub, wired to small PO installed Alpine amp under passenger seat.

The system sounds pretty good, the sub makes an enormous difference to the system. The problem is that it's unbalanced sound; in order to get a reasonable front/rear balance, I have to turn down the power on the amp driving the front almost to zero, which in turn severely limits the total volume of the system. I think the rear speakers need an amp to balance things out.

Where does the wiring for the rear speakers run? Is there a convenient location somewhere to hide a small amp like the Alpine? I don't think there's room for a 3rd under the passenger seat, and I don't think the wiring runs there anyway.

Additional consideration... It could be a coincidence, but as soon as I had the sub installed and that amp turned on, I started seeing an issue with tail light warnings. Specifically, I usually have a red light showing on my charging system until I rev the engine enough to engage the exciter on the alternator. No biggie I think. But since I connected the sub, if I turn on the headlights before I rev the engine enough to engage the exciter, I'll get a Tail Light warning. Which makes me think the sub is overtaxing the charging system/alternator. And if I add another amp it will get worse. I believe I have the original - or original spec - alternator on it, although I know it's missing the shroud so it might not be the right one. If I need more power, is there a good, easy alternator upgrade?

It's a '79.

RyanPerrella

I would replace the 2 channel amp with a single 4 channel and run all peakers minus the subs off that. Or eliminate the amp and run the speakers off the head unit. It probably puts out at least 15 RMS watts which is probably plenty unless you have brand new speakers.

bronto

Here's the head unit.

http://www.crutchfield.com/App/Produ...ures_and_specs

dr bob

Your installer tapped into the alternator excitation circuit when looking for a switch 12V signal. Have them fix that.

bronto

Thanks Dr. Bob. That installation was years - decades - ago, but it's a good tip. The main power for the amps does go to one of the always hot posts in the fuse panel; I know because the battery draining was the first thing I had to solve when I got it in summer of 2006. It turns out that the battery drain was the result of said hot post connection and a smoked amp that wouldn't shut off with the key. My quick fix was to toggle to hot lead, but ultimately replacing the amp with an identical one ( the Alpine) has solved this problem. But it's still wired to the hot lead. Any suggestions which lead it should be wired to?

Alan

Amplifiers should be directly connected to the battery. Dr Bob refers to the switcheed supply for the head unit.

Maybe its just a coincidence and your exciter circuit has a seperate issue. It certainly sounds like there is an issue with the alternator where it only generates at high RPM - this is not normal and it seems unlikely your new subwoofer draws a huge current...

How does the alternator behave with the head unit (and => all amps) off...

Alan

RyanPerrella

That head unit puts out pretty good power with 25 RMS watts. I would ditch the amp and run them all off the HU. That would solve your balance issues.

As for the other stuff it sound like bob is onto something

bronto

The head unit seems to behave correctly, as it powers on & off with the ignition key as it's supposed to.

The exciter behaves the same regardless of whether the stereo is on or not. And it does charge at low idle, once it's "engaged" (not sure of the right word). But when the car is cold, when I start the car the light is red until I rev it up to about 1200 rpm. Then the light goes off, and stays off even if the rpms go back down to 7-800. This behavior doesn't seem to be related to the stereo at all. And it worked this way even when I was protecting the battery by toggling off the amps when I parked. Since it was a serious power drain, I often wouldn't toggle the amps on at all, unless I was going for a long drive.

But, back to the original statement... When the headlights are on, and the exciter hasn't yet engaged, I get a Tail Light warning. And this is new behavior (more or less) since I hooked up the subwoofer and it's amp. If I engage the exciter before turning on the headlights, no Tail Light warning. There's definitely an issue there, the question is whether it's related to the amps being on or not.

Alan

Seems your alternator or the exciter circuit have an issue you need to fix. If the warning problem only occurs when the alternator is not generating - fix that issue first...

Alan

bronto

That's kind of why I asked both questions at the same time. If I need an upgraded alternator, maybe I should just do that rather than fiddle with the existing one.

RyanPerrella

There was just a thread about the Delco alternators rated at 105 amp that can be bought from Autozone for $79 or something. They come with 3 or 4 year warranties as well. You do need to wire in the new pigtail type connector but most stores sell these as well.

Do a search for "Delco" and you will find it, just posted last maybe 2 days ago. If you need a new alternator, i would definitely be tempted to go this route myself.

Alan

I don't think the issue is that you need an upgraded alternator - you just need one that works properly... yours doesn't!

if with the audio system off you only start to generate at 1200rpm you have a problem unrelated to load. If your charge light comes on then this could be the alternator exciter circuit coils/regulator not working correctly. Take it to an alternator shop and see if they can confirm it:

1) Has a problem (else it may be a car side issue)

2) Can it be fixed cheaply?

3) Can it be fixed and upgraded?

4) Can it be replaced with a better equivalent (for fit /connection)

I would not suggest just bying a new alternator untill you are sure thats the problem. Also fixing it may be very cheap.

Alan