help with settings on a multi meter to check charging system

[bigmic]

can somebody help me with my multi meter im not sure if it is my regulator or my alt im trying to do the tests with the multi meter only problem im havin trouble with the settings on the meter im not sure whats ac or dc or which one is the resistance and what no: it should be on(20,200,2000)

[stroker800]

  When checking  stator (motor not running) check to see if stator is grounded....you will check for contenuity between the stator and the cases,,this is in ohms.. when checking for current the stator puts out AC voltage,motor will be running,,DO NOT short out against cases when checking,,I don't have volts off hand,,,sorry  The regulator will be measured in DC volts,,they should be 12-15 volts DC,,,make sure regulator is grounded well...others will answer too..hope this helped some...
Dave

[ramcr913]

Bigmic:

Since you posted this in the shovel section, I am going to assume you are dealing with a shovel...

General stuff- If you are checking the alternator output from the front of the engine after unplugging the regulator- you will be looking for AC. Regulator plugged in, with the meter across the battery terminals, you will be looking for DC. Meters have different scales, but a general rule of thumb is to use the lowest scale possible. For example, if you are looking for 12V DC, and your scale options are 5v, 15v, 100v, etc, use 15v. Also, remember that for remainder of this procedure, ONLY DC cares about polarity. Red is positive, black is negative. When measuring resistance (ohms) and AC voltage, polarity is immaterial.  To troubleshoot the charging system, there are a lot of variations on the theme, but here is what I do:

1. CLEAN your battery terminals and the wires that connect to them.
2. CLEAN your negative cable to ground connection.
3. Charge your battery
4. Do some soul searching and convince yourself you did a good job of steps 1 & 2.
5. Set your meter to read DC. Set the scale to as close to > 15vDC as you can. Read the battery voltage (red to positive, black to negative).You should read 12v across the battery.
6. Get a helper, grow a 3rd hand, or use your teeth or alligator clips or whatever it takes to: Start the bike. Rev the motor to about 3600 RPM. You should read somewhere between 13.5 and 15 Volts. Blip the throttle a few times. As you crack the whip, you should see the voltage increase and decrease with engine RPM. If it remains 12v or skyrockets wildly past 15vDC, you got charging problems.
     
Now let's figure out if its your alternator or regulator:

7. Set your meter to read OHMS. You will be looking for a reading of 2-4 Ohms. So, set the scale to as low as possible. Touch the leads together and verify they read 0, signifying a complete lack of resistance, and assuring the meter is functioning correctly.
8. Oh yeah, shut the bike off.
9. Pull the regulator plug from the front of the block. Take a look at connections- if the regulator plug has not been securely/fully/tightly seated, you will see burnt-looking pins. This is common on shovels. (not to confuse he issue, but depending on what year shovel you have the pins will be in the block, or the regulator plug- sockets in the other)  After you fix the charging problem you may have to add an aftermarket "plug-holder-in gizmo", if you don't already have one.

10. Read the resistance across the 2 pins in the block where you pulled the plug. You should read between 2 and 4 ohms. (don't let the meter leads touch the block while you do this- at this point you will be on your knees with your reading glasses on).

      If you read nothing (no change to meter) then you have an open stator, it will have to be replaced. We will doubly verify it in a moment, below.

11. Next, check each pin to ground- one lead to the pin and the other to the cranckase (Remember, polarity is immaterial for this test). You should read "infinity"- that is you should see no change on the meter, signifying that there is no short to ground.
     
If the meter goes to zero from either pin (same as touching the leads together) then your stator has somehow shorted itself to ground and will have to be replaced. We will doubly verify it in a moment, below.

12. Let's verify the alternator output by checking its AC voltage- set your meter to AC. A safe setting for this test will be 110V.
13. Start the bike, and get help again.
14. Read across the pins as you did previously. You should read about 19 to 26 volts PER 1000 RPM. Again, the voltage output should "rev" when you blip the throttle. If you have no AC output from the alternator, your stator has toasted. You can stick your meter in a wall outlet to make sure its working correctly on the AC setting- look for 110-120 VAC.
15. If all checks out ok, take a look at steps 1 & 2 again. If you still have problems, repost and we will go from there.

Hopefully I typed this out OK, if I made a misteak I'm sure someone will step in and correct me. Hope this helps, let us know how it goes.

[bigmic]

thanks heaps but also can you tell me the symbols for resistence,ac dc,ohms etc.

[shov76]

Hope this helps...

  OFF                                    turn the multimeter off

                  V ~                             measure AC voltage difference
                            _____
                        V  - - - - -              measure DC voltage difference
                                                                 
                         W                      measure resistance

                       --> + )))                 test diodes
                                          ____
                  mA                        measure current when in microamps (~ for AC current;  - - - - for DC current)
   
              mA                           measure current when in milliamps (~ for AC current;  - - - - for DC current)
                                                  ____   
          A                                  measure current in amps  (~ for AC current;  - - - - for DC current)


Shov

[bigmic]

thanks heaps