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William Badurski (Billb)
Junior Member
Username: Billb

Post Number: 192
Registered: 6-2001
Posted on Sunday, July 20, 2003 - 8:33 pm:   

The original was the large red plastic box type (RTT101) located under the dash on the left end. They do tend to fail regularly. Unless you're concerned with originality, go with one of those suggested here, or switch to an internal regulator Delcotron like I did.... end of problems.
JRV (Jrvall)
Intermediate Member
Username: Jrvall

Post Number: 1989
Registered: 11-2002
Posted on Friday, July 18, 2003 - 7:14 pm:   

>>You could also always change to a Marelli alternator with built in regulator as used in later years and those run a couple hundred bucks.<,

If it turns out to be regulator or alternator, I highly reccomend upgrading to a modern real alternator (65 Amps or better)...you're AC Blower & Rad. Cooling Fans will love you for it.
Brian Keegan (4redude)
Junior Member
Username: 4redude

Post Number: 130
Registered: 7-2002
Posted on Friday, July 18, 2003 - 4:42 pm:   

I have some original RTT101 "red box" regulators available. Also, if your Italian is good, workshop manuals too.
rich (Dino2400)
Member
Username: Dino2400

Post Number: 375
Registered: 10-2001
Posted on Wednesday, July 16, 2003 - 9:37 am:   

Hi Terry, though apparently they are available for $150 from Jeff (and $175 from Dennis McCann for the finned version, plain version shows as out of stock), I suspect any number of voltage regulators could do the job. If you want to stick to Italian parts, Fiats of the 60s and 70s, regardless of model all used regulator part number 4062890 which runs about $65 new. This is the type with the points that is adjustable. Superformance in the UK lists the external regulators as used on the Dino 206/246 for about $30. I don't know how these compare to the Daytona regulators though since Superformance doesn't list parts by the Ferrari part numbers. It could be the same, it could be different. You could also always change to a Marelli alternator with built in regulator as used in later years and those run a couple hundred bucks.
Jeff Howe (Ferrari_uk)
Member
Username: Ferrari_uk

Post Number: 399
Registered: 12-2002
Posted on Wednesday, July 16, 2003 - 9:19 am:   

Hi all.

This from our technical support guy...

"He obviously needs to check through the charging circuit very carefully, especialy the earthing wires from the engine to the gearbox and the battery to the chassis. The most common fault with 365s is the voltage regular, but don't be fooled by the ammeter reading, they are renown for giving innacurate readings.

Regulators are in stock - #112786, retail �94.20, about $150.

They are usually hard to get so it would be a good idea to keep as a spare."

Hope this is of some help.
Mitch Alsup (Mitch_alsup)
Member
Username: Mitch_alsup

Post Number: 880
Registered: 4-2002
Posted on Tuesday, July 15, 2003 - 10:38 pm:   

If the batery was realy flat, like mine sometimes gets after sitting too long, the Battery in my F355 will take 20 amps (off a charger) for as long as 7 hours before dropping under 20 Amps and another 5 hrs until the charger thinks its fully charged. And it would almost crank!

The real way to tell is by voltage, if its still taking more than 10 amps and the voltage is greater than 13.5V-13.8V at the terminals on the battery you may have a regulator problem. But a really dead battery can take a surprisingly long time to fully charge.
Terry Springer (Tspringer)
Member
Username: Tspringer

Post Number: 663
Registered: 4-2002
Posted on Tuesday, July 15, 2003 - 9:25 pm:   

Thanks for the excellent advice!

The battery is a relativly new Optima. I drove around for at least an hour, the charging never dropped off after the problem cropped up.

I also remember hearing a very faint, rapid sort of clicking noise from under the dash. It was very faint, I though perhaps it was something passing through the AC fan. It was about the same time I noticed the heavy charging was not going away. I now assume it was the voltage regulator, but will still test and check as recommended.

Is the under dash regulator tough to remove? Where should I shop for a replacement or is it a generic or Fiat part?

Thanks again!
James Selevan (Jselevan)
Member
Username: Jselevan

Post Number: 669
Registered: 6-2002
Posted on Tuesday, July 15, 2003 - 3:05 pm:   

Terry - I agree with JRV, and would add a few things to look for. A bad cell in the battery could look like a short and draw big amperes from the alternator. However, a near dead battery from something left on (like the trunk light that does not go off when closed) will require significant (30-40 amperes) charging current FOR A PERIOD OF TIME. After 15 or 20 minutes of running, however, you should see the charging current begin to move down towards 10 amps. If it does not, then something else is wrong.

To test, I would place a charger on the battery over night. If when starting, the battery seems weak despite the charge, or if the amp meter reveals 40 amps of charging current after the overnight charge, then the battery has gone south for the summer.

Jim S.
JRV (Jrvall)
Intermediate Member
Username: Jrvall

Post Number: 1937
Registered: 11-2002
Posted on Tuesday, July 15, 2003 - 9:57 am:   

>>Is the voltage regulator internal to the alternator? Any easy way to test this? Ideas on replacing?<<

The Voltage Reg. is under the dash in the steering wheel area, and not the internal type(if still stock that is).

If the Alt. is truly charging that much, (which isn't a lot if accec. are used/needed) then you may have a Voltage Drawproblem killing the battery rather than a charging problem.

I'd start by checking for a Voltage Draw with Key off ( disconnect Battery grond cable and bridge cable battery pole with 12V test light, if light goes on you have a drain), if it was me (and I've done lot's of Daytonas), then proceed with checking charging condition second with any of a multitude of inexpensive Alternator Tester Tools.

HTH's
Terry Springer (Tspringer)
Member
Username: Tspringer

Post Number: 661
Registered: 4-2002
Posted on Tuesday, July 15, 2003 - 9:03 am:   

Driving the Daytona to the Porsche club meeting today (it was a big hit with the P-car crowd) I think I have a problem.

When I went to start the car, the battery was a bit weak. I barely turned the starter, but the car did fire normally and runs great. I noticed when driving however that the ammeter is showing a positive charge of close to the maximum 40 amps at anything over 2000 rpm. It showed this much charging the entire time I drove it, overall about 75 miles.

I suspect the voltage regulator is shot, allowing it to charge too much. I have an Optima battery installed, but dont want to ruin it. Anyone have any experience with the alternator/voltage regulator in these cars? Is the voltage regulator internal to the alternator? Any easy way to test this? Ideas on replacing?

I have not looked at the shop manual yet or tested the battery. I figured I would ask here first (yes im lazy).

Coming home in the cool air after a thunderstorm last night, with an empty road and the windows down I got the chance to push the car some on my favorite twisty road. MAN! This car is indeed FAST and a real blast to drive quickly. I gotta have this problem fixed before the weekend!

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