Electrical Sparking At Negative Battery Terminal After Alt. 4 Ga Power Wire

tell me you did NOT reinstall the stock 2G power wires to the + post on the back of the alternator. If so, REMOVE THEM and tape them off, unless you want to watch your car catch fire. Leave the 4 gauge power connected to the + post. You also must add an additional 4 gauge ground wire from the block to the chassis.

Have the charging system checked out -most auto parts stores will do it for free, What you are seeing is evidence that the alternator isn't putting out sufficient power.

consider returning the part after you have the result of the test.

They have a tester box that loads the electrical system and checks the voltage.

No.11 said:

Ahhh ok this is something they'd bring out to the car?

also, anyone know what the return process is for lmr? I don't want to be without an alternator, unable to drive the car for too long.

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Curbside service, they do it for free in hope of selling you something...

No.11 said:

ok something is not right with my 3g install...
my lights still dim when I put the windows down, or when the idle surges. What should I be looking for?

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Sounds like you have a bad connection.

• Make sure all of your connections are tight. Do a voltage drop test all along the power wire- measure at the battery, at both posts on the solenoid, at the back of the alternator.
  
• Make sure all of your grounds are tight, shiny, clean
• Make sure your stator wire connection is solid
• Check the ground strap from the back of the motor to the firewall
• CHeck the ground behing the battery
  
• Check the HEGO ground- orange wire behind the block on the firewall to the engine harness

Did you add an additional 4g ground cable from the block to the chassis. I highly doubt the new alternator is faulty.

The voltage drops are excessive, so your wire is less than satisfactory. If you are using crimp style connections, they could be the problem. In any case, I would replace the 4 gauge cable with one that had soldered lugs on it.

No.11 said:

my cable is a pa performance 4 ga power wire that I ordered from brothers performance because lmr was out of stock at the time. I would think this is a quality piece.

as for the rest of my wires on the 3g conversion, I didn't have a crimping tool so I soldered instead.

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Do the voltage drop testing as shown below to confirm your readings...


Voltage drop testing of connections and grounds.

Use a Digital Volt Meter (DVM) to measure the voltage drop across a connection or wire. Adding length to the test leads may be required, and does not affect the accuracy of the test. Use 16-18 gauge wire for the test leads if you have to lengthen them.

Voltage drop increases with the increase of current in a circuit and it also increases with heat. Put a maximum current load on a bad wire or connection and it gets hot and drops more voltage across the wire or connection. As it heats up, resistance increases which makes more heat. Round and round you go in a vicious circle until something catches fire or fails.

Voltage drop testing must be done while the usual load is on the circuit. If it is a starter, it has to be tested while cranking the starter. If it is lights, A/C or fan, they must be turned on high while testing. Fail to do this and you will not get accurate results

1.) Most grounds use the negative battery post as their starting point. Keep this in mind when checking grounds.
2.) The voltage will be small if the ground is good: less voltage drop = better connection.
3.) Be sure that the power to the circuit is on, and the circuit is being used in its normal manner. For instance, if it is a light circuit, the lights on that circuit should be powered on.
4.) To measure grounds, place one DVM lead on the battery negative post and the other on the wire or connector that goes to ground.
5.) 5.) Voltage drops should not exceed the following:
200 mV Wire or cable
300 mV Switch
100 mV Ground
0 mV to <50 mV Sensor Connections (sensors are low voltage devices and small drops can have a large effect on the devices dependent on sensor accuracy)
0.0V Connections
A voltage drop lower that spec is always acceptable.
6.)
See http://assets.fluke.com/appnotes/automotive/beatbook.pdf for help for help troubleshooting voltage drops across connections and components. .

No.11 said:

yep, doing that. Should I alsp put a load on the alternator as well? Turn on all lights, radio, plug in a phone to charge, and raise the rpm?

using an innova 3320 multimeter. Setting it to DCV during these tests.

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Yes there needs to be a load on any circuit that is going to be tested for voltage drops, and that includes alternators.

No.11 said:

so if I was getting that amount of voltage drop without a load, that means my reading with a load will be even higher, correct?

My multimeter should automatically be setting the range, yes? It just says dcv and then 10 megohm input.
I wish I was more electrically savvy

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The higher the current the greater the voltage drop across any resistance.

I have never seen your DVM and I have no idea what the specs and functions are. Google it and see what you get.

Since you have said that you have a low level of proficiency in electrical matters, here's some help before you get started.

Automotive circuits are mostly simple stuff: a power source, a connection path, a control device, a load, and a ground.
The battery/alternator is the positive power source.
The wire and fuses are the connection path.
Control devices are switches, relays and sensors.
A load is a light, motor, solenoid, relay coil or heater element.
In automotive circuits, grounds are the return path so the electrical power can flow from the load to the negative side of the power source.
Electricity flows like water:
Voltage is like pressure,
Current in amps is like volume,
Resistance is like the kink you put in a garden hose to decrease the pressure or volume.
Power is pressure multiplied by volume or voltage multiplied by current (amps)

Digest that, and you just got the first 3 days of Electricity 101.

Use some jumper wires (connection path and ground) to hook up a switch (control device), a battery (power source), a light bulb (load). Now make the light turn on and off with the switch.

That's the electrical lab for the first week of Electricity 101.

For free automotive electrical training, see Automotive Training and Resource Site . Once you are there, select online instruction.. I have personally reviewed the material and it is very good. If you are new to automotive electrical troubleshooting, I highly recommend you spend a hour or so going through the material. You'll save at least that much time troubleshooting problems.


Using a Multimeter or DVM
Almost every meter has a different method for showing an open circuit. An open circuit is one with a break in it somewhere. That break can be a switch turned off, a fuse blown, a lamp burned out, a bad connector, a damaged circuit board or a cut or burned wire.

Without reading the instruction manual that came with your meter, I would not try to guess what your readings mean.

Step 1.) Find the instruction book that came with your Multimeter or DVM. Read it and familiarize yourself with how it works and how use it. If you lost the book or didn’t get one with it, do a Google search on the web to find the manufacturer’s web site & download a copy of the manual. Remember that while some meters auto-range to find the correct voltage range, the Ohms function ranges are usually set by the selector switch. Most of the resistance testing done in automotive troubleshooting uses the lowest Ohms range possible.

Step 2. ) Make sure that you know what test lead plugs into which jacks on the Multimeter or DVM. There are usually several different jacks on most Multimeter or DVMs, and they have different functions. Make sure that your battery(s) in the Multimeter are good: if you have any doubts, replace the battery(s).

Step 3.) Once you are sure that the Multimeter or DVM is functional and you have the leads plugged into the jacks for Ohms ( the Ω symbol), do some simple measurements to make sure that you know how to use it correctly. Set the switch to the lowest range and touch the leads together: you should not see “nothing” but you should see 0.3-1.0 ohms. Measure a 60 watt light bulb: cold it will measure about 17.5 Ohms. It you measure it while it is hot, the reading will be greater.

Step 4.) Make several test measurements using the ohms function and the DC volts function. Remember all resistance measurements must be done with the power off the circuit. This avoids false readings and possible damage to the ohmmeter.. Repeat steps 3 & 4 until you are sure that you can do it without making any mistakes.

Step 5.) Then see | Repair Guides | Understanding And Troubleshooting Electrical Systems | Basic Electrical Theory | AutoZone.com and carefully study ALL the information under the Heading Chassis Electrical, Basic Electricity – Understanding & Troubleshooting

Step 6.) Apply what you have learned and make the test measurements using the information in the wiring diagrams & my previous posts.

Don't be in too much of a hurry to bolt all the new, pretty, shiny parts together. Take the simple steps now and you will save yourself lots of time and trouble later.