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WB9MCW · 12-07-2008

Yea Hadi you need some REGULATION -- now go to a good shop and confirm!!

See if this thread gets you to the bottom of it all -- Early C4 -- proly similar (wires and testing at any rate) for our Z at least get you on course for finding the problem.

http://forums.*************.com/c4-t...d-battery.html

Here is the tech tip for the later larger alternators my guess is the same as our Z

http://www.*************.com/techtip...=254&TopicID=2

Another c4 bench test alt thread

http://forums.*************.com/c4-t...lternator.html

there are a few things you need to know.
1. the alternator is a constant potential charging device. That means there is a preset voltage limit in the alternator voltage regulator.
The alternator tries it's mightiest to achieve that at all times.
2.When you first start the car, the alternator wants to get to that voltage, and it kicks in more field voltage to accomplish this.
The field voltage is a function of the voltage regulator based upon it's constant battery voltage sampling.
3.so, cold, the battery has sat all night, it's achieved it's lowest unloaded voltage, and then just started the engine. The voltage wire on the plug on the alternator feeds the sample voltage to the regulator (CHECK THAT PLUG) then if the voltage is lower, the reduced battery voltage biases the voltage regulator, and the alternator starts out at 105 amps. As the battery voltage comes up, the field voltage goes down, ending up with the load and the battery setting the alternator load at any given second.
4. The alternator generates heat.
a. the heat of the alternator is respective of the load.
b. Load is based upon battery voltage
3. there is a thermister in the regulator that reduces the amount of voltage sampled by the alternator, reducing the voltage and the load.
4. reduced voltage and load reduces the battery voltage when the car is hot. The hotter the alternator, the lower the voltage to a point. The battery could overcharge at elevated temps and sulfate excessively, so this is a good thing.
5. The alternator doesn't produce much output below 550 RPM.
6. The alternators don't do well at extremely high temps.
7. Notice the voltage cold, and the voltage hot. it may vary by 2 volts or more.
8. overhauled alternators may be compromised by the overhaul methods.
9. there are aftermarket methods of reducing the alternator temp.

Third thread >>>92 Vette

http://www.corvetteactioncenter.com/...regulator.html

4th Thread 89 C4

http://www.digitalcorvettes.com/foru...d.php?t=108875

the ******* are the block on our favorite forum that is blocked at the server level ---tis what it tis --- too bad for this because every now and then a link to that forum is in order for stuff just like this!!!

Well you can proly guess what forun it is and finger it out!!

GOOD LUCK HADI --- KNOWLEDGE IS POWER!!!

12-07-2008	#13
WB9MCW Join Date: Dec 2003 Location: McHenry, Il. Posts: 6,584	Re: Charging system Problem ! Yea Hadi you need some REGULATION -- now go to a good shop and confirm!! See if this thread gets you to the bottom of it all -- Early C4 -- proly similar (wires and testing at any rate) for our Z at least get you on course for finding the problem. http://forums.***********.com/c4-t...d-battery.html Here is the tech tip for the later larger alternators my guess is the same as our Z http://www.*********.com/techtip...=254&TopicID=2 Another c4 bench test alt thread http://forums.*********.com/c4-t...lternator.html there are a few things you need to know. 1. the alternator is a constant potential charging device. That means there is a preset voltage limit in the alternator voltage regulator. The alternator tries it's mightiest to achieve that at all times. 2.When you first start the car, the alternator wants to get to that voltage, and it kicks in more field voltage to accomplish this. The field voltage is a function of the voltage regulator based upon it's constant battery voltage sampling. 3.so, cold, the battery has sat all night, it's achieved it's lowest unloaded voltage, and then just started the engine. The voltage wire on the plug on the alternator feeds the sample voltage to the regulator (CHECK THAT PLUG) then if the voltage is lower, the reduced battery voltage biases the voltage regulator, and the alternator starts out at 105 amps. As the battery voltage comes up, the field voltage goes down, ending up with the load and the battery setting the alternator load at any given second. 4. The alternator generates heat. a. the heat of the alternator is respective of the load. b. Load is based upon battery voltage 3. there is a thermister in the regulator that reduces the amount of voltage sampled by the alternator, reducing the voltage and the load. 4. reduced voltage and load reduces the battery voltage when the car is hot. The hotter the alternator, the lower the voltage to a point. The battery could overcharge at elevated temps and sulfate excessively, so this is a good thing. 5. The alternator doesn't produce much output below 550 RPM. 6. The alternators don't do well at extremely high temps. 7. Notice the voltage cold, and the voltage hot. it may vary by 2 volts or more. 8. overhauled alternators may be compromised by the overhaul methods. 9. there are aftermarket methods of reducing the alternator temp. Third thread >>>92 Vette http://www.corvetteactioncenter.com/...regulator.html 4th Thread 89 C4 http://www.digitalcorvettes.com/foru...d.php?t=108875 the ***** are the block on our favorite forum that is blocked at the server level ---tis what it tis --- too bad for this because every now and then a link to that forum is in order for stuff just like this!!! Well you can proly guess what forun it is and finger it out!! GOOD LUCK HADI --- KNOWLEDGE IS POWER!!! Last edited by WB9MCW; 12-07-2008 at 04:34 PM.