[ChevelleSS_LS6]

Originally Posted by 406 ss monte

doc, you are so very right. why do they need to know if my car has a/c to tell me which u-joint it takes? cross referencing is a thing of the past.

i'm going to rebuild the alternator. where should i get the rebuild kit? i have rebuilt this alternator before, but the only thing i didn't put in new was a rectifier. it's a 78 amp alternator, but if i can get it to put out more than that, that would be alright too. thanks for all everybody's help, i couldn't have done it without it.

by the way, whats the differance between a 10 si, 12 si, & 15 si alternator's?

I usually get my stuff at the local NAPA.. ASE certified parts guys know their stuff I tell ya! The prices aren't bad, the parts are pretty goodm and at least at the one near my house the service is awesome.

[docvette]

Doc here,

The kit can be had an any good reputable auto parts house like napa or others..Hell, Auto Zombie carries them too..Last one I bought was about $15 , but given the price of everything else may have gone up..

If you feel the need to upgrade..I suggest the CS 140 Alternator..IF your running extreme loads..Couple of hundred bucks..basically simple to wire..and into the 21 St century..

If you plan to rebuild the alternator...

• Remove it from the car
• Get about 2 or 3 cans of gunk, go to the coin wash, spray it with the gunk..let it soak 5 minutes..THEN set the wash to degrease, spray that for 5 minutes..Then rinse for 5 to 10 minutes..Allow dry time OR better yet air blow dry..
  
  
• Halve the cases
• Remove the brushes, brush holder/followers (depending on kit)
• Remove the Bearing
• Remove the bush (depending on kit)
• Remove the regulator and install the new one.
• Remove the rectifier Diodes and install the new ones.
• With a fine Emory or Croakas Cloth, Burnish the brush pickups or (Slip rings) on the rotor assembly until smooth and shiny.
  
  
• Install your new bearing, but before you do..get a SMALL sharp punch, carefully put a dimple in the race each 1/3 rd the way around. This will prevent the Bearing from EVER spinning in the race..is a tiny bit harder to put the cases back together, you have to tap the halves with a rubber mallet.
  
  
• Install the bushing. (depends on kit)
  
  
• Where the brushes are at the rear end bell, there should be a small hole that goes through to the brushes..insert a #40 drill bit or paper clip with the brushes fully compressed up..this will hold them off the slip rings while you insert the end bell.
  
  
• Before reassembling the end bells to the body, inspect the windings..you are looking for no warn insulating paint, or glypt, and where the windings terminate, no melted or splattered solder or cracked joints If needed, Ohm the windings out..but these usually last forever..and if they failed before..you'd know it..
  
  
• Install the end bells to the body and properly "Clock it for your application, be sure the end bells are straight..and (if needed) tap the bearing half end-bell with a mallet..and secure with the bolts..
  
  
• Lastly spin it up by hand and insure it spins free and quiet..Inspect the front fan blade, and reinstall on the car..

If you notice the brackets or hardware is power white, remove them and media or water blast them , you have electrolysis going on there (mounts are aluminum and hardware/engine is steel..What were they thinking??)

Get some electrical bonding paste for aluminum wire..and coat the bolts, and mounts anywhere they touch steel..



That should give you a much better unit than you can buy over the counter..that will probably out live the car..

Doc

[406 ss monte]

what does the rectifier do? doesn't it conver a/c to d/c current? what do the diodes do?

[leejoy]

Originally Posted by docvette

Doc here,

Not to mention SOME of the guy's at Auto Zombie are not the sharpest crayons in the box...

Need to know what year the fragrance trees fit, and Super-size those trees for ya??.....

Uhhh...Alternator...That's like a starter ... Right? ...

Humm...Voltage Regulator??...OK...How many PSI??...

Be sure you get a guy that at least LOOKS like he knows a spark plug from a trailer lamp plug..

Doc

I always assume the guys at auto parts stores are "dummies" before I even get there. that way if they turn out to be helpful I am unexpectedly pleased and satisfied. If they are total "dummies" I do not get upset or aggravated because that is what I expected anyway. Same with fast food. I expect it to be lousy or just ok. If it's better than that, well then good for me.....

One time I went to one of those national chain auto parts stores (expecting a dummy to be helping me) and there was this "genius" dude that offered to help me. He had like an IQ of like 10,000 and was a graduate of some specialized exotic auto service school. I always wondered why he was working there when he could have probably been a lead engineer at some automobile manufacturer.....

ok - enough of my ramblings for now. I'll shutup and go away.

[docvette]

Originally Posted by 406 ss monte

what does the rectifier do? doesn't it conver a/c to d/c current? what do the diodes do?

SIMPLE QUESTION WITH AN INVOLVED ANSWER:
Long read...

Doc here,

A rectifier does exactly that...Rectifies AC to DC voltage..and depending on how configured, is how well it does just that..1/4 wave, 1/2 wave, Full wave..usually From one to four diodes..(Battery charger to Filtered DC bench supply)

Diodes are usually semiconductor devices...(unless you are an old radio tech...then they are Passive devices) Or as fondly remembered ..TUBES..


A Diode, within reason (and tolerance) will conduct in ONE DIRECTION only..(OR Forward bias..) Think of it as a Check Valve for electrons..one way flows smooth, the other hits a brick wall..(again , within tolerance) To follow the flow..just follow the printing on the diode or schematic..



The direction of flow here will be from anode to cathode..

If you put a lamp on the cathode side to ground and 12 volts on the Anode side the lamp will light..reverse the wires on the diode..The Lamp will NOT light..in Fact, put the ground on the Anode side and power to the Cathode side...you have effective isolation..NOTHING happens..reverse it and the diode goes up in smoke.

When selecting a Diode..your concerns are Max Current..say, 1 amp...and PIV or peak inverse voltage..Say, 50..that voltage which WILL travel back through the diode and crowbar it shut..(making it just a Bidirectional wire..)

There or several other types of Diodes also, that can pick up Transmitted signal,(signal, switching, gunplexer) Reverse polarity protect a device (Zenier) Rectifier (single to Bridge types)

A Zenier is a voltage sensitive diode that auto~reverse biases when a specified voltage is seen between its conductors and purposely causes the diode to fail closed to prevent damage to a digital device that has seen a reverse polarity..(Faster than a speeding Fuse..More effective than a hamhanded Tech..) basically it senses a reverse voltage and crowbars shut across the power and ground of the device..no matter how many fuses you put in there they will just blow out UNTIL you repair / Replace the zenier..so you can't damage the unit EVEN if you correct the polarity issue..

A signal or switching diode does just that..detects signals in the air, in the circuit or however you configure it..Remember the "Cats Whisker " radio you made in school?? that was a diode..

A Gunplexer is a Diode array, that is configured as an antenna..used in devices from everything to PD Radar Guns..To Television Satellite antennas..to wave guides for your home dish antenna..

Switching diodes configured in the right manner will give you a transistor...and more than that on a chip..an Integrated circuit..to millions of them, a Microprocessor..you can follow the evolution from TUBE to Dime size Chip..

A Bridge rectifier, is commonly used in Well filtered, Regulated power supplies (bench supplies) as well as Power supplies for Radio and television , computers (with a slight twist..) to Car Alternators..and consists of 4 diodes placed in a "Bridge" configuration..


Full wave Bridge rectifier (Bad Dwg..Ignore AC~+ /- ...does not exsist in AC..sorry..)

If you note, the AC enters the bridge in Half wave stages..Then look forward of that..you'll see the the DC voltage WITH + and - polarity..

Were this a bench supply, the stage before it, would be a transformer that plugs into the wall..110 VAC, and drops it To 12 VAC..(for example)

The stage after it would be Capacitive filtering done with Electrolytic Caps and Mica bypass caps..

The stage after that would be a bleed off resistor..then on to a Regulator Chip..

From there out to a a Current meter , and Voltage meter as well as a fuse protection device ON BOTH the DC output side and The 110 Volt Transformer side..

Sounds pretty complex? Nope bare bones stuff..lower scale supply I wouldn't use for Digital powering..but good for a Novice to test a harness in the car..The current is dependent on the value of the transformer amperage , the Current handling of the Bridge, the WVDC (working Voltage DC ) of the caps..Depending on how Configured..from 1 MA to 10000 Amps..(slight exaggeration..)

NOW, yall wonder WHY I get up on my soapbox when I read it's OK ..I can use a battery charger for a testing supply...Without the fuses..without the current meter..this is a diagram of a Basic $29.95 charger...



On the top drawing , almost all 60 cycles of the AC are filtered out in each cycle..The Caps, the Regulator..help shape and buffer anything else..

On the lower diagram you'd be lucky to see 1/4 of a wave filtered at all leaving 3/4 of each cycle to AC..Don't know about you..Which would you rather have powering your $4000 Stereo..or your $800 performance ignition..or your $400 Dollar Computer..and it's sensors??

Try it yourself with a trash radio..put it straight to a charger and turn it on..I betting you won't hear a thing except a Very loud hum..I'm going with a top line bench supply!

An Alternator works the same way as the Bridge above..and more (usually 6 diodes) to rectify Raw AC generated within..The more diodes that fail or break down the LESS useable output it has...Same applies to the regulator EXCEPT it can slightly bias backward and impose a load on the battery just sitting...(Morning Sickness..) Overnight Dead battery's will start showing up..

OK , off the soap box... There is everything you DIDN'T want to know about diodes..Oh , this is just a breif overview..for more get a basic Electronics book..and do your own research...

NOTE: No Text was harmed in the creation of this post..

Doc

[406 ss monte]

beleive it or not, i think i understood some of that. doc you are the man!

[406 ss monte]

well i put a new alternator on it & it seems to be doing better. i tested it again like before & it read .08 amps. any thing under .8 amps are fine right? if it is .08 amps should be great then. i'm leaving the battery connected & we'll see if it's any better in a couple weeks. i believe it's fixed but i don't want to jinx myself.

with any luck this bad boy is fixed, now i just need to fix the rear caliper that popped on me today. never had this happen before, i nailed the throttle, hit 2nd gear, then hit the brakes & they worked for a second then went to the floor. i looked & there was brake fluid running out of the back right drum. it has brand new wheel cylinders on both side & one popped. wonder why?

thanks for everybody's help. i've learned a little something & that why we're all here right?.. i couldn't have done it without you guys helping me. thanks a bunch.