sandro

Yo guys,

Im getting a low Voltage (12.4v with engine running, and 11.8-12.0v in the "acc" key position 3) reading both at the 1 Farad Power Capacitor digital readout in my trunk, and from my Passport X50 Radar on the dash.

I have 1996 E320 with 177k miles, still living on the factory original alternator. (assited by an Optima Yellow Top deep cycle battery)

After 7 years of pumping the Diamond Audio Components, and 2 12" Infinity Kappa 5.1 Dual Voice coil subs, what are the chances my alternator is shot???

What are your thoughts? I'd like to make the right repair without braking the bank!

Thanks a million...

aardvark

Lets face it. With 177K on an original alternator you may be in for a new one.
Around here I am able to find a local shop that will rebuild and rewind an alternator, and at a considerable savings. I would think you could find the same in your neck of the woods if you dig in the yellow pages. Not only can they rebuild but they can upgrade for more juice if needed.
On the stereo front. I have seen the additional draw have adverse effect on the alternators. They push harder, and have to play catch up when the draw is increased. Normally that should not be much of an issue, unless you are running a "Radical" system.
I witnessed a friend with a Gold Wing motorcycle with his trunk unit full of amplification and speakers literally kill the battery. The alternator wouldn't even keep up with the stereo draw, so it is plausible.
Dunno your system, and really am not overly qualified to make an electrical judgment, but I do know what I have witnessed.

Also, the voltage to me sounds a little low.

Aardvark.

ohlord

a small 90 amp alternator on a 96 anyway.And it can be replaced for $180.Have you had the voltage checked at diode excitation click on speed or are you testing it at idle?
You should be seeing in excess of 13.5 volts and any good parts store or auto electric shop can run it on a meter and test it for you.Auto stores do it for free.schucks kraggens etc.
Be nice if the 150amp from the m113 v8 would fit ,but it has a different body size.

MARK CUMMINS

The Alternator from a S Class will work its output is 143 and 150 AMP

112/113 alternators will interchange

And Since he (The OP) has a 1996 with a 104 the larger alternator will fit the engine as well

Nice write up on Mercedes shop on this

sandro

For anyone fishing for info.

It was the alternator after all...

The alternator gave way on the 5 south one day shortly after I posted this thread. Total loss of power at 80 MPH in the fast lane. Had to tow the car off the freeway.

Sierra Grande

I went through 2 alternators in my '87 Accord. After installing an Optima and a 1 farad capacitor I never had anymore problems. It even seemed to help the lights keep from dimming. I never put another system in another car without the aforementioned parts. Sounds like your alternator fought the good fight, just got old and died.

mike430sport

I just had my alternator rebuilt. Cost me $180. I also have subs in the trunk, when my daughters stroller isn't in it

Figuero

The battery does not assist the alternator. It's visa versa.

Sierra Grande

That's not bad. Was that for installation too? Did you have them wire it for more amps? I have heard you can do that. I bought 1 heavy duty alternator a few years ago for a pickup, I think it was 150 amps, cost $250.

mike430sport

I am having some major work done to my engine timing chain and rails. I initially went to the shop for the alternator. I changed the voltage regulator and it didn't fix the problem. I had to hook up my battery to a charger over night to drive it to the shop. No, I did not have them wire it up for more amps. I didn't think about that. Car still in the shop hope to get it back soon

Sierra Grande

Sorry to hear of your timing chain woes. I saw your posts and pics. I was just mentioning the alternator wiring, I have no real idea if it can be done on an MB alternator.
What kind of subs/amp do you have? I'm going to replace my stock HU when I get home Wednesday and if that's not enough to make me happy than I may consider some subs. Never had a sedan, only hatchbacks, so I'm wondering how other people get bass from the trunk to the cab.