There are two methods of testing an alternator: with an ammeter and with a voltmeter (or multimeter).

If you have an ammeter that can handle over 100 amps, you can use it to determine how many amps the alternator is generating while being run at approximately 2,000 RPM. At this engine speed an alternator should produce at least 45 to 50 Amps and some produce upwards of 100 Amps.

If you do not have access to an ammeter you can test using an inexpensive voltmeter or multimeter for voltage. Your alternator should supply between 12.0 and 15.0 volts at 2,000 RPM. Any measurement outside of this range indicates a defective alternator.

The last diagnostic method is the most widely used, yet most basic method for determining if an alternator is defective. This is commonly referred to as "Dying Light Syndrome" and as the name suggests this is simply a judgement call one makes when the lights (and other accessories) start to fade and die.

An engine can operate for over an hour after the alternator stops working, until these tell-tale signs begin to appear.

Many repair shops, upon hearing this from their customer, will skip the testing completely but continue to charge the diagnostic fee.

REMOVAL

Start by disconnecting the battery to prevent any electric shocks.

Next, remove the drive belts or serpentine belt. If the car is equipped with drive belts (V-Belts) you will need to loosen the adjusters or accessory mounting bolt that keeps it tight. This will often be the top mounting bolt on the alternator or power steering assembly.

If the car is equipped with a serpentine belt (Multi-V Belt) you should find a spring-loaded idler pulley that must be unloaded to let the belt slip off. Idler pulley arms often have small "square" holes in them designed to fit with a 1/2" or 3/8" ratchet (without a socket).

Next, remove the mounting bolts that hold the alternator in place. Keep track of where each bolt goes as they may be of different sizes, lengths, and even different thread pitches.

Finally, disconnect the wires from the back of the alternator (sometimes up to three separate wires or harnesses) and remove the alternator.

If you were unable to test the alternator in the vehicle or the tests were inconclusive, take the alternator to your local auto parts store. They will usually do this over the counter and free of charge.

INSTALLATION

Installing your new alternator is simply the reverse of the removal. But, before bolting it in take a thorough look at the new alternator to be sure it matches your old unit exactly.

Since many new alternators are actually remanufactured units, they may have been assembled in the wrong position; that is, the front and back portion of the casing may have been bolted together in the wrong alignment.

Other times, certain options may cause your alternator to be positioned in a different location at the factory. Take for example, dealership installed air conditioning vs. factory installed air conditioning.

REMOVAL:

Depressurize fuel system by cranking the engine for a minimum of 15 seconds with the fuel pump fuse removed, or by using a fuel pressure gauge.

Disconnect the negative battery cable.

Remove fuel from fuel tank by pumping out through filler neck using suction hose.

Support fuel tank and remove fuel tank support straps. Lower fuel tank partially and remove fuel lines, electrical connectors and vent lines from tank. Remove fuel tank.

Remove any dirt that has accumulated around fuel pump attaching flange so that it will not enter fuel tank during removal and installation.

Turn fuel pump locking ring counterclockwise using fuel tank sender wrench or lightly tap the locking ring around evenly around.

Remove fuel pump and bracket assembly.

Remove seal gasket and discard. Do not try to reuse the seal because as soon as it hits the air, it swells and it will never seal again.

Carefully remove pump from it's mounting. Some pumps are held in with a small clamp or are placed inside a rubber mount.

Unplug the wires from the fuel pump. Take note of which wires go where. Most pumps are "idiot proofed" but there are some that can be connected backwards. Also, some pumps have their wires soldered on. You will need to unsolder the old ones and solder the new ones on.

INSTALLATION:

Clean fuel pump mounting flange, fuel tank mounting surface and seal ring groove.

Put a light coating oil on a new seal ring to hold it in place during assembly and install it in fuel ring groove.

Install fuel pump and sender assembly carefully to ensure that filter is not damaged. Ensure that locating keys are in keyways and seal ring remains in place.

Hold assembly in place and install locking ring finger tight. Ensure that all locking tabs are under tank lock ring tabs.

Secure unit with locking ring by rotating ring clockwise using fuel tank sender wrench until ring stops against stops.

Position fuel tank to vehicle and support tank while connecting fuel lines, vent line, and electrical connectors to appropriate places.

Install tank in vehicle and tighten straps.

Install filler tube and attaching screws.

Install a minimum of 10 gallons of fuel and check for leaks.

Reconnect the battery ground cable.

Turn the ignition switch to the ON position for three seconds repeatedly (5 to 10 times) until pressure gauge shows at least 30 psi.

Remove pressure gauge, start engine, and recheck for leaks.

Start the vehicle and check for leaks. If you need to replace any fuel lines, make sure you get fuel line rated for high-pressure fuel systems. Also the hose clamps used on fuel lines are special clamps. You should replace them whenever you remove them and never use the worm type "mini clamps."

This is the kind of job where a second pair of hands comes in handy. Gas tanks are awkward to work with and trying to juggle a gas tank and disconnect hoses and connectors by yourself can be a challenge.

REMOVAL

Disconnect the negative battery cable.

Disconnect fuel tank hose at the fuel pump, and plug the hose with a bolt or wooden dowel to keep any fuel from flowing out wires. Check the hose and if it is frayed or cracked, replace it with new fuel line hose.

Disconnect the outlet line to the carburetor. Use a wrench on the fuel pump fitting and another on the line nut.

Remove the two attaching bolts and remove the old fuel pump. Clean off any old gasket material from the mounting surface of the engine.

INSTALLATION

Apply a coat of gasket sealer on both sides of the new gasket. Put the attaching bolts through the new pump and slip the gasket over the bolts.

Install the new pump on the engine. Make sure that the rocker arm in the pump is against the eccentric inside the engine, or that the push rod is correctly installed in both the engine and the fuel pump. If the push rod slides out, you can pack it with some heavy grease to hold it in place while you install the pump.

Attach the fuel outlet line that runs to the carburetor. If it's difficult to connect, remove the other end of the line from the carburetor. Connect the line to the fuel pump, and then reattach the other end to the carburetor. Use a wrench to hold the fuel pump fitting and tighten the line nut with another wrench.

Attach the fuel inlet hose from the gas tank, and the vapor return hose (if the vehicle is equipped with one). Tighten all clamps.

STARTER REMOVAL

Disconnect the negative battery cable.

Remove the battery cable attached to the starter, either from the solenoid or the starter itself.

Remove any other wires attached to the solenoid if it is mounted on the starter. Write down or note the wire positions so you can replace them correctly.

Remove the mounting bolts (usually two on General Motors and Chrysler or three on most Fords). Most bolts attach horizontally through the mounting flange. On General Motors cars there may be a shim between the engine and starter. If there is save it, it must be used with the new starter. Remove any support bracket that holds the front of the starter

Now comes the fun part, getting it out. You may have to turn the wheels to one side or the other. You may have to disconnect an idler arm on some Ford models. On other cars you may have to remove or loosen transmission oil cooler lines or brackets, the exhaust pipe, flywheel housing cover, cross member, ground strap, oil pressure sending unit or other parts to give you enough clearance to drop the starter down.

STARTER INSTALLATION

Install the new starter in the reverse order of removal. If you took out any shim(s) on the General Motors type starter be sure you install them with the new starter. This will usually be correct, but if there is a abnormal noise when the engine is cranking or a whine after it starts, you may need to adjust the shims as follows:

If there is a starter noise when you crank the engine, remove one shim.

If there is a high-pitched whine after the engine starts, add a shim one at a time until the noise disappears. DO NOT use more than four shims. To add a shim, loosen the inside bolt, remove the outside bolt, add the shim and then retighten both bolts

Reattach the battery/starter cable to the starter. If the solenoid is starter-mounted, reconnect any other wires to it in their original positions.

Reconnect the battery negative cable.

SOLENOID REPLACEMENT

Solenoids are located either on the inside fender in the engine compartment or on the starter itself.

To replace the inside fender mounted solenoid:

Disconnect the negative battery cable.

Remove the positive cable from the battery, the cable going to the starter, and the small wire or wires connected to the solenoid. Write down or note their exact locations.

Remove the attaching screws and take out the old solenoid.

Install the new solenoid in the same location and reattach the wires and cables. Make sure all the connections are clean and tight.

Reconnect the negative battery cable.

To replace a starter-mounted solenoid:

Remove the starter. (See above.)

Remove the braided strap from the starter to the solenoid.

Remove the mounting screws and/or bolts. Remove the solenoid housing. You may have to rotate the housing one way or the other to get it off. On some starters the plunger and spring may be loose. On other, the solenoid plunger stays in the solenoid, and the end will have to be worked off the starter shift lever.

Install the new solenoid in the reverse order of removal. If the plunger stays with the solenoid, the end must be engaged with the starter shift lever. If the solenoid plunger remained attached to the starter, insert it in the solenoid. Make sure the spring is in place between the plunger and solenoid body. Hold the body in place and tighten the attaching screws.

Reconnect the cable and wiring when you install the starter.

Reconnect the ground cable to the battery.