What should the voltage be on a GM alternator?

Ideal Voltage Output Ideally, the GM alternator should be putting out anywhere between 13.5 and 14.5 volts. A voltage regulator helps regulate the voltage that an alternator provides. If the voltage dips below the optimal range, then the regulator kicks in to get the alternator to make more voltage.

How do you wire an alternator in a Chevy?

How to Wire a Chevy Alternator. Connect the #2 terminal to the positive terminal on the battery. This terminal can also be jumped directly to the BAT terminal. This line is used to regulate the power generated by the alternator. Attach the alternator fan belt to the pulleys on the engine and alternator.

What does high voltage mean on an alternator?

A high voltage reading, typically above 15 volts, indicates a problem. Though the regulator is designed to protect electrical components of the vehicle, sometimes it does fail. When the voltage output of an alternator reaches a higher-than-recommended threshold, it will destroy the battery and ruin the electrical system of the vehicle.

How many volts should an alternator put out at idle?

An alternator should put out between 13.5 and 15 volts of power. The alternator should be tested with the engine idling and electrical accessories, such as the radio and headlights, turned off.

What should the voltage be in a Chevy alternator?

When your Chevy is running, you should get approximately 12.8 to 14.0 volts of power, and there is a quick and easy test to determine if your regulator is over- or under-performing. Place the red lead of you multimeter onto the positive battery terminal on your car battery.

When does a GM alternator need to be replaced?

A GM alternator that is producing too much voltage must be replaced. When a car does not start or the lights are dim, it may be because the voltage output has dropped lower than 13.5 volts. When this happens, the battery is not being charged, and the electrical systems of the vehicle will fail.

What is the voltage regulator on a Chevy?

The voltage regulator is built into the alternator on all Chevys made from the 1980s to at least 2010. Simply put, the regulator restricts the amount of voltage being sent to the battery. Without a regulator the battery would receive upwards of 30-volts of power while charging, which would quickly damage or destroy your battery.

What happens when the voltage is too high on an alternator?

If the voltage dips below the optimal range, then the regulator kicks in to get the alternator to make more voltage. The opposite happens when voltage levels read too high. The regulator backs off and allows for the voltage to wind down until it is back within its normal range.

Where is the alternator in a stock car?

The place where you connect this wire to the main power wire in the harness is the place where the alternator will maintain the proper ~14V in the system. The junction block where you connected the battery and vehicle feed wires where the regulator used to be is a good choice for mostly stock type systems.

Where are the mounting points on a GM alternator?

The “clocking” of a GM alternator is the way the front and back case halves are put together. The front case half has the two mounting points, and the back case half has all of the electrical connections.

When did GM start using alternators in cars?

produced in some form after 1963 (that was the first year for alternators in GM vehicles) and try to scavenge brackets from a later motor. Whatever you do for brackets, you’ll need to make sure it’s all secure, that you can adjust the alternator belt properly, and that all the pulleys line up. You may need to put

Where is the voltage sensing wire on a GM alternator?

The Number 1 wire on the 10- or 12-SI is connected to the charge warning light on the dash. The Number 2 wire is what is called the voltage sensing wire. When converting from an external voltage regulator to an internal such as the 12-SI, many enthusiasts merely connect the Number 2 voltage sensing wire directly to the output terminal.

What’s the maximum output of a GM alternator?

Assembled with all original GM components, the model 10SI alternator had a maximum output rating of 63amps. Output rating is determined by the windings in the alternator, and not all model 10SI alternators had the same windings.

Can a pulley be swapped for an alternator?

You can even swap your original pulley over to the new one if you need to. For the fans, be aware that the fan design changes on the later 12SI series alternator are there to keep it cool in higher output models, so the fan that goes with the alternator should always be used.

How does a voltage regulator work on an alternator?

A voltage regulator helps regulate the voltage that an alternator provides. If the voltage dips below the optimal range, then the regulator kicks in to get the alternator to make more voltage. The opposite happens when voltage levels read too high.

What does an alternator do in a car?

It is responsible for keeping the battery charged in the car, which in turn, keeps all the electrical systems functioning properly. The alternator creates direct current, measured in volts, to achieve this. If it creates too little or too much voltage, this can indicate a problem with the alternator, and it may need attention.

How to identify your GM alternator USA built high output?

This is just a quick visual identification guide for Delco type alternators. First Alternator used on GM Vehicles to replace old DC Generators. External regulator mounted on the firewall.

When did Delco alternators start replacing DC generators?

This is just a quick visual identification guide for Delco type alternators. First Alternator used on GM Vehicles to replace old DC Generators. External regulator mounted on the firewall. First used in 1963 on the Corvette. First internally regulated alternator used by GM. Replaced the externally regulated 10DN. Again, first used on the Corvette.

When did the GM 21si alternator come out?

First internally regulated alternator used by GM. Replaced the externally regulated 10DN. Again, first used on the Corvette. Wasn’t into full production until about 1962. The 21Si and 22Si are near identical cosmetically. Internal differences are…

When was the alternator first used on a corvette?

External regulator mounted on the firewall. First used in 1963 on the Corvette. First internally regulated alternator used by GM. Replaced the externally regulated 10DN. Again, first used on the Corvette. Wasn’t into full production until about 1962.

GM typically runs a fusible link wire between them for overload protection and they can go bad, mimicking a bad alternator. A voltage drop of .25 volts or less is Ok and the alternator is bad. A voltage drop of .5 volts or more means the wire is bad.

What causes an alternator to go over base voltage?

If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

Why does the Volt gauge fluctuate while the engine is running?

If you have voltage fluctuations while the engine is running it is an indicator of a problem with the charging circuit, or a major short. The battery condition is not related to the voltage guage unless it is really shot, and we can see this is not the case. Either you have something kicking in and causing a major draw, or a bad voltage regulator.

Is it normal to exceed generator amperage when idle?

With enough electrical loads “ON”, it is easy to exceed the generator current (amperage) output when the engine is at an idle of 600-700 RPM. This is a normal condition.

How to diagnose an alternator or electrical problem?

Diagnosing alternator problems can be a bit tricky because the electrical system in a car comes from two places, the battery and the alternator. I’ll give you a little background so you can understand what both systems do. The battery has one primary function, which is to start the car.

What happens if you have a bad alternator in your car?

The car won’t start at all. If the problem is a bad alternator, your car will slowly lose power. You’ll be driving down the road, your lights will dim, and you’ll lose power and die. If the problem is with your battery, then you’ll generally only have trouble starting your car since that’s the battery’s main function.

Is it normal for an alternator to not charge?

Still, it’s perfectly normal for others to see the alternator not charge at all intermittently. One test is not enough if you are diagnosing a charging system problem. All too often, the alternator is condemned as the source of the problem if only battery voltage is present with the engine running.

Can a battery voltage test be done on an alternator?

One test is not enough if you are diagnosing a charging system problem. All too often, the alternator is condemned as the source of the problem if only battery voltage is present with the engine running. If this is the case, it only means that the alternator is not charging, but does not reveal why.

What are the fuses on a 2001 Chevy Silverado?

Repair Topics > Fuses > Chevrolet > 2001 Chevrolet Silverado… IGN A Fuse #3 40A Starter Relay, Ignition Switch IGN 1. TURN. SEO IGN Fuses PARK LP Fuse #12 30A Park Lamp Relay. Healamp and Panel Dimmer Switch Park Lamps STOP LPS Fuse #14 20A VEH STOP and CHMSL Fuses. Trailer Wiring (LH.

What to do if your alternator is over charging the battery?

Ask an assistant to start the engine and hold engine speed at about 1500 RPM. Measure voltage across the battery with your DMM. You should get 0.5 to 2 volts higher than base voltage. If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty.

Are there any electrical issues with my 2004 Silverado?

GerryGarcia answered 5 years ago I’m having the same issue on my 2004 Silverado with 143K miles. The gauges turn off and the ABS, parking brake lights flash on with the audible chime then a few seconds or minutes everything returns back to normal. Sometimes it does it 1-2 times a day or whenever it feels like it.

Is there a problem with an alternator overcharging?

The subs have all been wired correctly. 500 watts rms amp with 0 gauge wiring. Alternator Overcharging? I had the same problem once with an 06 D****. It was charging at between 15.3-15.8 it was tweakin out my hids then a month or so later the alt would only put out 7-8v. Replaced with new alt and it went back to normal.

What should my alternator voltage be while driving?

While driving the voltage reads about 15.2 to 15.5. All my electronics and everything else is working normally. I do have subs though but usually the voltage should drop. Any suggestions? You do not have the required permissions to view the files attached to this post. Re: Alternator Overcharging? Sounds like the alternator might be on its way out!

How many Watts Does a 2010 alternator have?

I guess being a 2010 the battery is ready to get changed out. The subs have all been wired correctly. 500 watts rms amp with 0 gauge wiring. Alternator Overcharging?

Why does my alternator have a low output?

Low output can be caused by extreme drops in temperature and rainy conditions, but this quickly fixes itself once the car heats up. If there is a real issue with the alternator, you may not know until you use several of your car’s electrical components all at once.

What was the performance of the 2003 Corvette?

In fact, the C5-R’s season-long performance was so strong that one of the only changes made to the 2004 Corvette would be to commemorate the 2003 racing season. RACING: As Corvette celebrated its 50th Anniversary, the Corvette Racing Teams helped commemorate the special anniversary by placing 2nd and 3rd place at the 24 Hours of Le Mans.

What kind of suspension system does a 2003 Corvette have?

As a result, the 2003 Corvette produced a quieter, flatter ride with more responsive and more precise handling, especially during high-speed driving maneuvers. The 2003 Corvette featured the F55 Magnetic Selective Ride Control Suspension system.