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Alternator help on old chevy 350

13K views 5 replies 3 participants last post by  agent spliff 
#1 ·
Hello all, I have an old 3/4 ton chevy truck (1982) it came with a 6.2 deisel in it, and I put in a 383 that I made from a 4bolt main. I have always used the wiring that was in the truck when I got it, and that may be part of my problem. The batery died in it about two weeks ago, so I put in a new one, and no problems until today. After I was driving around for a while, I parked and when I tried to start it, it was very slow to turn over. Lucky for me my engine always starts on the first crank, otherwise I would have been stuck. I got home, and I pulled out the multimeter and I cheked to see what the battery was at....14.12 - 14.25, so I put on the heater and lights....still at 14.25....so I am thinking wth??? why did the truck seems to be near dead an hour ago? I watched the voltmeter in the truck drop when the lights when on, then go back up. So I start looking at the wiring to the alt and battery, terminals etc. All I could think off is that maybe I am using the wrong gauges of wire, or I have it hooked up wrong. I have had problems on and off with the battery and alternator since I put in the motor. The alt is only five months old, and the battery is about two weeks. The wiring to the battery from the alt is a 2gauge from a old car stereo, I am assuming after reading one of the articles in the knowledge base that this could be the problem, I would also like it if I could get a schematic, or a link to one, of how I should be wiring the charging system, and the gauge of wire I should be using. See I live in Vancouver BC, I bought the truck off a guy who was lived in surrey. If any of you have ever been to surrey, or seen the people that live in bridgeview, then you know what I am talking about. To make a long story short the previous owner was a crackhead, and I am still sadly enough using his wiring. I have changed everything else on the truck, but wiring problems in it are rampant.....many gremlins. When I first got the truck, I am not sure how it even started, as it had no negative lead attached?!? If someone could point me in the direction of a schematic with wire gauge I should be using...that would be sweet.

Thanks all

Agent Spliff
 
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#2 ·
Doc here, :pimp:

Sounds like you need some diodes in the alternator..

BECAUSE it is new does not mean it is any good!

Do a draw test on the battery just sitting..it should be between .3 and .8 of am amp (depending on what memory type equipment you have running) be sure you other draws are off or defeated..Domes, hood, trunk glove lamps..or you will get a false reading.

If it is above an amp, Totally disconnect the alternator, retest, If it falls back in spec, go get a kit or a new alternator..it's shot..

IF it does not, do a parasitic Draw test , (as above , meter configured for AMPS , highest scale, one probe on the cable the other on the battery) and remove ALL the fuses and relays..plug them back in one at a time until the reading shoots up..that is an offending branch circuit..disable or repair as needed, and continue on until all are back in place.

YOUR GROUNDING MUST BE PERFECT ALSO!!
It won't charge a capacity until it is..to do that:

For your Ground Buss, Set it up as follows:

BE sure First, You have A 4 gauge Cable (for stock battery location, OR , 0/0 or 0/1 Cable for a trunk location) from the battery, to any handy bolt at or NEAR the starter on the block .

Using a short run to something like a seat belt bolt, or body bolt just adds resistance, the body is insulated..(has road paint and sits on rubber mounts) this , makes for a "Poor or no" Bonding situation..
  • that makes resistance..
  • Resistance makes Heat..
  • heat melts things and further insulates the bond,
  • which makes more heat..and so on..until you no longer have a good bond..

To install a proper ground buss system, This MUST be done:
  • 1 ) Run a properly gauged (0/0 or 0/1) Ground cable from the battery in the trunk, Or A 4 Gauge cable for a stock located battery, to any handy bolt at or near the starter on the block. From that same bolt get a 4 gauge Battery cable at the parts store, that has two 3/8 ring terminals on each end and attach it there and to the Frame. Make this run as short as possible.

  • 2 ) Next get some 10 gauge wire and ring terminals, run two wires from your bolt on the block, to the Firewall, Burnish off all the paint, grease or oil or dirt from the area, Install a sheetmetal or Self Drilling Tech screw using a star washer as well as a lock washer.. and the other 10 gauge wire to the Alternator ground lug, bracket or mount bolt and attach with star and lock washers.
  • 3 ) Next get some Wire Braid, (expensive! about $10 for 5 - 6 inch pieces! ) Check Radio Shack for this, OR cheaper yet, get some RG 8 Coax cable, about 10 feet. Should run you about 15 cents a foot.

HOW TO MAKE WAY DURABLE CHEAP GROUND BRAID:
--------------------------------------------------
  • 1 ) carefully Slit the insulation from the cable with a Talaban Boarding pass (box knife) .


  • 2 ) Peel away the insulation until you just have the center dielectric and braid left, then carefully press the ends of the coax cable BRAID together like a Chinese "Finger puzzle"


  • 3 ) Slide the dielectric and center conductor out. remove it and toss it..


  • 4 ) On a work bench, Flatten the Braided shield out, use a round weight like a full paint can to roll over it.
------------------------------------------------------

This will be your braid cable, just Cut to smaller length's as needed, and tuck the cut ends into a crimp terminal and crimp the ends on..

IF you can Solder, Tin the ends before you tuck the ends of the cable into the terminals, then Tin the barrel of the terminals, then insert the cable and crimp..

Then heat the terminal and braid, feed some solder into the opposite end as the heat is being applied, let it melt and FLOW or WICK toward the heat..until the terminal barrel is filled and is smooth and shiny..

that is a good joint..gray and rough is a "Cold Joint" and you'll have to start over..
  • 4 ) NEXT, install braid from the radiator support to the frame, Fenderwells to frame , hood to firewall, Doors to door posts, gas flap to body, tailgate / Trunk to body. Install a cable or Braid From the Fuel tank Ground lug where the sender, Fuel line is to the frame..burnish the frame, use star washers and sheetmetal or Tech (self Drilling screws) on the frame.

  • 5 ) At each point the wire is grounded, Burnish ALL the paint and grease off to bare metal. Use a proper star-washer and lock. Use sheetmetal or Tech screws where no screws are available.


It sounds like a lot of work, but after you assemble all the parts, it's only a few hours to do..and you'll end up with a system that will work reliably for many years to come..and can eliminate that from your troubleshooting list.

Remember: GROUND is the other Half of your 12 volt circuit AND is equally as important as having POWER to the device!

Doc :pimp:
 
#4 ·
alternator help

Or your starter to be failing. Didn't you say the problem was that it cranked over slow when hot? I think I'd do a voltage drop test on the starter ground and power circuits before I rewired my car. I've had the same symptom on a car with a dirty ground from the battery at the block. It's be a shame to do all the work you're talking about if it was only a matter of cleaning and tightening a bolt on the block.
 
#5 ·
agent spliff said:
The batery died in it about two weeks ago, so I put in a new one, and no problems until today.
(Assuming Cold first of the day start, after sitting for a few days)


agent spliff said:
After I was driving around for a while, I parked and when I tried to start it, it was very slow to turn over. Lucky for me my engine always starts on the first crank, otherwise I would have been stuck.

Assuming the battery WAS NOT charged after being dead, on a Home Charger for 12 hours at 10 amps..Alternators will not..nor were they intended to Recharge a Zero to hero dead battery..

Their Function is to replace a high current "surface charge" lost during startup and support the electrical system ONLY while doing that..It will not replace a deep cycle charge lost unless your going on a cross country road trip with no system draws..




agent spliff said:
I got home, and I pulled out the multimeter and I cheked to see what the battery was at....14.12 - 14.25, so I put on the heater and lights....still at 14.25....so I am thinking wth??? why did the truck seems to be near dead an hour ago? I watched the voltmeter in the truck drop when the lights when on, then go back up. So I start looking at the wiring to the alt and battery, terminals etc. All I could think off is that maybe I am using the wrong gauges of wire, or I have it hooked up wrong.

YES , in fact you would see 14.4 volts at the battery..PURE output from the alternator..NOT the battery charge state..the battery may be FLAT dead..(or close to it..) and show 14.4 at the terminals on a running/Charging alternator..and YES, the draws would not effect the reading because the regulator is holding them high, (not cycling) due to the low battery.

By virtue of the fact the terminals show a 14.4 running , it sorta precludes a mis~Wire..it IS charging..and the regulator PROBABLY is working..




agent spliff said:
I have had problems on and off with the battery and alternator since I put in the motor. The alt is only five months old, and the battery is about two weeks.

The wiring to the battery from the alt is a 2gauge from a old car stereo, I am assuming after reading one of the articles in the knowledge base that this could be the problem,
Take several days, and go through removing any "Hacks" , butt splices, Added ring terminals, cut and taped wires, and replace with new wires and Soldered Joints..or you'll be plagued with problems forever.


agent spliff said:
I would also like it if I could get a schematic, or a link to one, of how I should be wiring the charging system, and the gauge of wire I should be using.
If it is a standard, 63 amp , 3 wire, Delcotron, Internally regulated..This is how one is connected..NO add ons..no extra's..



SIMPLE as pie..

The "RED THERMAL" wire is a FUSE LINK or MAXI FUSE, about 70 amps worth..BE SURE you add one or the other to prevent future Fire..



That goes to the #1 Terminal...either will look like this and install on the solenoid side of a 10 GAUGE RED wire..to the alternator.

The #2 and #3 Wires May be 14 Gauge RED , and BROWN wires..to The Alternator output (RED) and Charge lamp (BROWN).

The #4 Terminal is a 10 Gauge BLACK that runs to your ground buss system..Don't forget this wire..It is as important as the #10 RED output wire!!

Half of a 14 volt circuit won't charge a Battery, much less even light a small indicator lamp..a Circuit is JUST that ... TWO sides , POWER and GROUND to function..remove either side..you have nothing.

(Single Fuse link)



(Fuse Link Binding post and main buss power on a well designed home system )



(MAXI FUSE and holder)



(Burned out Fuse Link)



Choose any one of the link systems and properly install them for fire protection..This is what may happen when you get tired of replacing them because the "High Power Audio Amp" keeps blowing them out..and you stick in a piece od 0/0 wire instead..



The Fire Department , Traditionally lets these BURN until the battery EXPLODES, OR the cables BURN all the way through, and just control the fire..BECAUSE no matter how much water you throw at it..It won't go out until you remove Fuel, Ignition and Air..an Electrical fire will flare right back up when you move the water away because it has constant ignition (Battery Power shorted to ground) until it dies or is disconnected..unlike a carb fire..




Agent Spliff said:
To make a long story short the previous owner was a crackhead, and I am still sadly enough using his wiring. I have changed everything else on the truck, but wiring problems in it are rampant.....

many gremlins. When I first got the truck, I am not sure how it even started, as it had no negative lead attached?!?

If someone could point me in the direction of a schematic with wire gauge I should be using...that would be sweet.

Thanks all

Agent Spliff
It might be time to evaluate the system and see if it is worth buying a new Wiring Kit from Ron Francis..If it's as bad as you say..I'm Betting it is...

In addition to that you need to set up a ground buss system..which no kit provides..simple, few parts are needed, and take you about 1/2 a day..

For your Ground Buss, Set it up as follows:

BE sure First, You have A 4 gauge Cable (for stock battery location, OR , 0/0 or 0/1 Cable for a trunk location) from the battery, to any handy bolt at or NEAR the starter on the block .

Using a short run to something like a seat belt bolt, or body bolt just adds resistance, the body is insulated..(has road paint and sits on rubber mounts) this , makes for a "Poor or no" Bonding situation..
  • that makes resistance..
  • Resistance makes Heat..
  • heat melts things and further insulates the bond,
  • which makes more heat..and so on..until you no longer have a good bond..

To install a proper ground buss system, This MUST be done:
  • 1 ) Run a properly gauged (0/0 or 0/1) Ground cable from the battery in the trunk, Or A 4 Gauge cable for a stock located battery, to any handy bolt at or near the starter on the block. From that same bolt get a 4 gauge Battery cable at the parts store, that has two 3/8 ring terminals on each end and attach it there and to the Frame. Make this run as short as possible.

  • 2 ) Next get some 10 gauge wire and ring terminals, run two wires from your bolt on the block, to the Firewall, Burnish off all the paint, grease or oil or dirt from the area, Install a sheetmetal or Self Drilling Tech screw using a star washer as well as a lock washer.. and the other 10 gauge wire to the Alternator ground lug, bracket or mount bolt and attach with star and lock washers.
  • 3 ) Next get some Wire Braid, (expensive! about $10 for 5 - 6 inch pieces! ) Check Radio Shack for this, OR cheaper yet, get some RG 8 Coax cable, about 10 feet. Should run you about 15 cents a foot.

HOW TO MAKE WAY DURABLE CHEAP GROUND BRAID:
--------------------------------------------------
  • 1 ) carefully Slit the insulation from the cable with a Talaban Boarding pass (box knife) .


  • 2 ) Peel away the insulation until you just have the center dielectric and braid left, then carefully press the ends of the coax cable BRAID together like a Chinese "Finger puzzle"


  • 3 ) Slide the dielectric and center conductor out. remove it and toss it..


  • 4 ) On a work bench, Flatten the Braided shield out, use a round weight like a full paint can to roll over it.
------------------------------------------------------

This will be your braid cable, just Cut to smaller length's as needed, and tuck the cut ends into a crimp terminal and crimp the ends on..

IF you can Solder, Tin the ends before you tuck the ends of the cable into the terminals, then Tin the barrel of the terminals, then insert the cable and crimp..

Then heat the terminal and braid, feed some solder into the opposite end as the heat is being applied, let it melt and FLOW or WICK toward the heat..until the terminal barrel is filled and is smooth and shiny..

that is a good joint..gray and rough is a "Cold Joint" and you'll have to start over..
  • 4 ) NEXT, install braid from the radiator support to the frame, Fenderwells to frame , hood to firewall, Doors to door posts, gas flap to body, tailgate / Trunk to body. Install a cable or Braid From the Fuel tank Ground lug where the sender, Fuel line is to the frame..burnish the frame, use star washers and sheetmetal or Tech (self Drilling screws) on the frame.

  • 5 ) At each point the wire is grounded, Burnish ALL the paint and grease off to bare metal. Use a proper star-washer and lock. Use sheetmetal or Tech screws where no screws are available.


It sounds like a lot of work, but after you assemble all the parts, it's only a few hours to do..and you'll end up with a system that will work reliably for many years to come..and can eliminate that from your troubleshooting list.

Remember: GROUND is the other Half of your 12 volt circuit AND is equally as important as having POWER to the device!

Doc :pimp:
 
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