Dying Altenators

Have you done an electrical charging system check?

Checked your wiring to make sure something isn't crossed or open?

I suspect your regulator is wacko and is your problem source.

Larry

Agreed, sounds like the regulator.
Over the years I've been through a few on the Rapier.

If you have a bad battery connection the voltage can climb very high and fry the regulator or rectifier.

A sick regulator can let the voltage climb - this can fry the HT coils, bulbs and the rectifier.

Sean,

Does your Pantera possibly still utilize the oem voltage regulator? Electro/mechanical voltage regulators sticking open or closed was a common electrical system failure, back in the days of electro/mechanical voltage regulators. They have solid state replacements that drop right in without any changes to the cars wiring required. I am in agreement with Larry & Derek that your problems sounds like classic voltage reg trouble.

Of course, there are modern high output alternators available with built in voltage regulators, they will require a bit of simple rewiring.

your friend on the DTBB

Sean,
Go with George's suggestion...the one wire alternator with the built in regulator. I am not saying they won't fail but they don't seem to. Also, you get to eliminate some wires from your system. That is never bad!
Most of the vendors can sell you a good one.

Cheers!
Mitch

I am about to change to a 100amp alternator. My 65amp will not keep up with my Flexilite fans.
I have been told that if I change from my existing 3 wire to a 1 wire, the charge light in the dash will no longer work. Is this true?

Johnny

For the most part Johnny you are correct. The gen idiot light will not function. There are a few, and I mean very few, that offer a lead to connect the light in a one wire altnerator. One of the things you give up for a cleaner connection.

Johnny,

There are alternators with internal voltage regulators having truly only 1 heavy wire connection, and there are those that have several wires. Often both types are referred to as one wire alternators. The only advantage of "true" one wire alternators is they reduce the amount of wiring in the engine compartment, a concern for owners of show cars. In a Pantera, the wiring up front really isn't visible to an observer peering into the engine bay from the rear of the car, and therefore there is little advantage for a one wire alternator, even in a Pantera show car.

There are several disadvantages to the one wire alternator. I do not recommend a one wire alternator, and suggest the Ford 3 wire alternator instead (voltage regulator is still internal to the alternator).

I fished around the internet and found this essay on the subject:

http://www.madelectrical.com/electricaltech/onewire-threewire.shtml

Your friend on the DTBB

Thank you for that. I think I will stick to my 3 wire. Can anyone suggest a good place to buy one? I want it to be reliable, and light weight if possible!

Johnny

Johnny. Agree with George regarding the 1-wire vs. 3-wire alternator issue. I ended up with a new Tuff Stuff 7078RC 100 amp, 3-wire alternator via eBay for $110 (shipping included). I installed a new electronic voltage regulator at the same time. I imagine The alternators are also available through most on-line performance shops. The RC version is chrome. So, it looks really nice when you've got the firewall cover off.

You can check it out here: http://www.tuffstuffperformance.com/products/part.asp?partid=139

Enjoy,

Ron

Thanks for the feedback guys. I'm in China right now and don't get to check in too often.

The last three have all been 100 amp alt's with internal regulators. They are the three wire type and my idiot light goes on when I'm past the point of no return. I'm working with Pat Mical on this and he is pretty sure we just keep getting bad altenators but it is starting to seem too unlikely to me. Maybe I should still use an external regulator?

Had a look at http://www.madelectrical.com/electricaltech/onewire-threewire2.shtml

The odd thing is that all the diagrams of the 'three wire' only show two wires...

Is the third wire missing from the diagram for the idiot light?

The Lucas units I'm familiar with have 2 wires, one big fat cable to the battery/loom and one skinny wire to the idiot light (negative goes through the alternator frame).

quote:

Does your Pantera possibly still utilize the oem voltage regulator? Electro/mechanical voltage regulators sticking open or closed was a common electrical system failure, back in the days of electro/mechanical voltage regulators. They have solid state replacements that drop right in without any changes to the cars wiring required. I am in agreement with Larry & Derek that your problems sounds like classic voltage reg trouble.

My voltage regulator fried a month ago.I have my dash apart now because I traced a burn't wire to my gen. warning light.The wire jacket was melted at the regulator and gen.warning light.Looked good in between.My advice to anyone with the OEM regulator is replace it quick.

After research and recommendation here, I stuck with the 3 wire alternator!

OK....now I am really confused. Everything seems to have healed itself. After recharging the battery, it has been fine now for three excursions (close to home since I don't trust it yet!). I am really thinking there is something shorting out in the wiring harness somewhere in the car, but it only happens intermittently. The wires to the idiot light and to the amp gauge have all been replaced. There must be a gremlin somewhere else in the soup.

...Buy the 100 amp Alternator from 'Hall Pantera'!! Not only does it have a Internal regulator, It also has a Intenal Cooling Fan. Yes, the 'GEN' light must be disconnected and the two wires going to that light, joined together; in order for 'it' to charge properly. I have had mine installed for over three years; from then on, I have never had to so much as think about it again...

When upgrading the alternator from 60v to 100v or more should any wiring changes be simultaneously made such as to the external regulator?