SLOW BATTERY DRAIN

We don't know what current is Alice's tender capable of providing, it could be just 1 amp or even less. If the battery "tender" can provide 3A, I would call it a (small) battery charger.

 

I found on my 1990 348 the parasitic drain that was killing the battery was the "brain boxes" in the front of the center console. These two black boxes control the crazy mad mouse seat belts and are always "ON" when the battery is connected. I could hear a relay clunking when connecting the battery. Once I removed these units and converted the belts to manual the problem was eliminated.

 

When everything is good, the "normal" battery drain is in the range of 0.03 to 0.05 A (30-50 mA). With this level of battery drain, a 0.25 A battery maintainer could probably do the job provided the battery is almost 100% full when connected. If you have higher drain than mentioned, 0.25 A may not be sufficient. Have you measured your battery drain?

 

Your battery tender is bad. A fully charged battery should be 12.7v.

 

Have you measured the parasitic drain of your battery?

 

Clean the bullet connector under the airbox to the starter...You haven't given details of what happens when it doesn't start. is it NOTHING, or a big click? is it cranking at all/just slowly?

sjd

 

@rifledriver, I have 3 355's , all FHP and one in each variant.
Two questions for you:
1) do you know a good psychiatrist ?
2) I am in Virginia....do you know of a reputable shop that can rebuild my alternator ? My issue is strange...I have a 1 of 1 Gated GTS in Blu Pozzi...really great car but twice now I have lost my battery after driving 25-50 miles....no warning...just warning lights and then nothing. My flat bed driver is now on my christmas card list, and I know all his kids names. Joking aside this is vexing..Could it be that in as little as two weeks my battery could get that weakened.
While my car looks really nice on the back of a flat bed, I much prefer good inputs at 75 MPH into the twistys. Have any sage advice other than to answer question 1 ?

Appreciate it and cheers, Jon

 

I have not yet found a reliable replacement for the one that retired.

 

Time to start carrying a fully charged spare battery in the funk.

 

Most of the time it's just the voltage regulator, which can be replaced without even removing the alternator from the car iirc. It's a standard denso part, usually like $40. In a pinch you could buy a similar capacity denso alternator for a Honda or Toyota and swap out the regulator, though it's a lot cheaper to buy it separately.

 

Where are you in VA? Sportscar workshops in Richmond do most of the local Ferraris. Most likely your voltage regulator is fried and that's an easy fix, see above.

 

@bobzdar , I will contact them. I am in charlottesville so not so far away from me. Is there a test to see if it actually is the voltage regulator ?

 

I don't know if there's a way to test that is the regulator, but it was cheap enough (~$40) and it was visibly fried, so I just replaced mine and it fixed the problem.