Tools and Tips

Tools – Section 1

Your choice of tools can play a big part of the quality of your work. If you want to know how good a mechanic is, look at his tool box. A good mechanic knows what tools to use for the job, and knows how to use them.

A good tool can make all the difference in the world. Top of the line tools, of course, would be Snap-On or Mac. You don’t have to spend that kind of money on tools, just to change your alternator, but don’t buy a set of wrenches at the Dollar Store either. Choose a brand that is moderately priced, and carries a guarantee, for your best value.  Pro mechanics love Gear wrench. They’re like a ratchet and a wrench, built into one.

Try to use 6 sided sockets and wrenches wherever possible. If a bolt starts to round off while you’re trying to remove it, don’t get discouraged. Apply liquid wrench or your favorite rust buster. Tap the head of the bolt, and around where the threads would be. Tap the head of the bolt hard enough to smash some metal back into the hexagon shape. Then tap the socket back onto the bolt. (Hint) The harder you have to tap the socket on, the better grip it will get.

Here’s a trick to save some knuckle busting:

1. Place the wrench squarely and completely onto the bolt

2. Hold the wrench on with one finger.

3. Tap the wrench counter
clockwise with a hammer.

Try not to ever let yourself get upset or frustrated. Many mechanical repair problems that require tools cannot be solved easily. Sometimes, all you have to do is step back and think. A tool is only going to work well for you, if it is being used properly and you’re making sure you use the right tool for the job.

Digital Voltmeter – Section 2

How to Use a Digital
Voltmeter (DVM)

One of the most important tools for charging and starting systems diagnostics is the digital voltmeter (DVM). Some people refer to them as digital multi-meters or DMM’s since most of them are capable of testing ohms and continuity.

For our purposes we are mostly interested in DC voltage. This is symbolized on most meters as “DCV” or a straight line. You will notice all digital voltmeters have three holes for the wires to plug in. The black wire or “common” goes in the middle. The red wire plugs into the + sign which would be labeled DC Voltage.

Turn the power switch to
“on” and we’re ready to go. Some test leads (or the red and black
wires) have optional alligator clips that screw on. We suggest using the
alligator on the black or negative terminal (-) and leaving the red or positive
(+) terminal as a pin.

The more expensive meters are self scaling, which means they will automatically adjust the read out display to the setting it needs to be. Some digital volt meters require the proper scale you need, to be set manually. For example: a Radio Shack 22-183A digital volt meter has a selector switch 300mV which is for measuring extremely small voltages. The “mV” means millavolt scale.

The next scale is a 3, then 30, 300, and 3000. Since automotive voltages are under 15VDC we could read them on any scale above 3, but we can read most accurately on the 30. Now, lets measure the voltage in a car battery. Turn the selector to DC volts, then select the proper scale.

The digital volt meter should have the black wire in common, and the red wire in DC Volts. Place the black test wire on the negative terminal of the battery, place the red test wire on the positive terminal of the battery. The display should be showing you the condition of the battery being tested

How To Remove A Starter – Section 3

1. Turn ignition off. Remove negative (ground) cable from battery.

2. Make sure vehicle is secure on jack stands and wheels are blocked.

3. Remove all cables and wiring from the starter solenoid. Use color tape to identify location. Tape
wires that are on the same terminal, together as a group. This would be a great time to use the close up function on your digital camera.

4. Loosen the starter mounting bolts. Note any support brackets, shims and any type of heat shield.

5. Remove mounting bolts while supporting starter body weight with one hand, or secure a rope around body of starter and tie off other end so starter can’t fall and cause bodily or mechanical damage.

6. Note the location of shims if used (normally on some GM’s) as they may stick to the starter or the engine block.

7. Inspect old starter (core) in 2 important areas.

a. Inspect starter drive teeth visually for chips, then swipe a magnet in the pocket that the bendix sits in. Excessive metal on magnet means you may have a worn or damaged flywheel and new starter life expectancy will be diminished.

b. Examine the threads on the copper stud where the main battery cable bolts on. If there is any black carbon or evidence of burning, this means there was a  faulty electrical connection. Clean the cables and wires with a piece of sandpaper and apply a light coating of silicone grease or lithium grease to all parts before reassembly.

How To Install An Starter -Section 4

1. Make sure ignition is off and negative battery cable is removed from battery.

2. Make sure vehicle is secure on jack stands and wheels are blocked.

3. Place starter in position on block. Install all previously removed mounting hardware and mounting bolts to manufacture spec’s.

4. With a piece of clean sandpaper (approx 80 grit) clean all wire terminals and battery cables on both sides. Apply a thin coat of silicone or white lithium grease to all surfaces including new solenoid. Reconnect all electrical wires to the correct terminals. Extreme care is necessary to properly tighten electrical connection nuts to a high enough torque without breaking plastic solenoid cap. This is done by placing a wrench on the nut BEHIND the cable you are tightening. The
use of lock washers is not recommended.

5. Reconnect negative battery cable to battery.

How To Remove An Alternator – Section 5

1. Disconnect negative battery cable from battery.

2. Charge battery. If you don’t have a charger, take the battery to be charged. Do NOT skip this step!
(Even if the battery is new, even if the battery still starts the car, even if your headlights are still bright) An new voltage regulator installed on a somewhat discharged battery will suffer irreparable damage, then fail in as little as three months.

3. Draw a picture or find sticker under hood of belt system. This may seem like an unnecessary step, but most often proves to be a valuable time saver.

4. De-tension belt with proper tool and remove belt from alternator pulley. Most mechanics completely remove the belt from the vehicle to inspect it at this time.

5. Unplug and disconnect all wiring and cables. Use paint stick or colored tape to assure exact

6. Remove alternator mounting bolts and remove alternator.

7. Thoroughly inspect area around alternator pulley. Any black fibers from the belt on the alternator itself should be considered either defective belt or tensioner.

How to Install An Alternator- Section – 6

1. Insure battery cable is removed from negative terminal.

2. Insure battery is fully charged.

3. Install alternator and alternator mounting bolts.

4. Install all electrical connections.

5. Install belt according to drawing or vehicle sticker.

6. Make sure ignition is off, install negative battery terminal. If battery is being completely re-installed, always install negative terminal last.

7. Place voltmeter on battery, it should read over 12.5 but under 13.5VDC. If it reads too high turn
the headlights on for a minute then retest.

8. Start car. Check voltage.  It should read 13.2-15VDC. Allow car to idle for 2-3 minutes. Make sure ALL accessories (particularly rear de-fog and AC) are off.

9. Use EXTREME caution for the next step. Turn car off. Remove key from the ignition. Carefully feel
temperature of alternator where the stator laminations are exposed. This is the area that is not aluminum, on the side of the alternator, right in the middle.  This should not be getting so hot that you can’t hold your hand on it without getting burnt. It wil get warm but not so hot you couldn’t leave your hand on it for 10 seconds or so.

10. If it is too hot, the battery needs charged more. If it’s just getting warm with no accessories on after 2-3 minutes of idling and the voltage is 14-15VDC you’re done.