Quick Answer

You Asked What wires go where on alternator?

Wiring Connections

Exciter wire is connected to the L terminal of an alternator and is used to turn on the voltage regulator. Excitor wire is needed to generate the voltage required for the alternator to start running. The positive and negative cables are small and connected to the respective terminals of the battery.

What color wires go to alternator?

Find the three cables that connect to the alternator terminals. You will see them hanging nearby: One is a red cable, the second black, while the third is usually a striped cable and may be colored green/yellow or blue/brown. The color can vary, but you can identify the cable, as it is thinner than the other two.

What is B+ and D+ on alternator?

B+ is the battery + connection ( ie the main output terminal) W is the connection for a tachometer. D+ is the warning light connection ( without which it will probably not function) D- is the battery negative connection.

What is D+ and D on alternator?

The way I understand the setup, D+ measures the voltage at the battery, and the delta between that and the preset voltage in the regulator drives the field to increase/decrease the output of the generator.

What are the 3 wires for on a alternator?

The three wire types in a three-wire alternator include the battery positive wire, the voltage sensing wire, and the ignition input wire. The battery positive wire connects to the starter. The voltage sensing wire connects to the battery, and the ignition wire connects from the alternator to the key switch.

Is there a ground wire on the alternator?

The last wire that will need improvement is the ground wire from the battery to the engine block. The alternator is grounded to the engine block by its mounting points so the engine block itself becomes an electrical ground distribution block. You just need to find a suitable bolt to secure your additional ground wire.

What are the terminals on an alternator?

A key to identifying your alternator terminals

Terminal Definition Notes
N Neutral Centre point of a Y-connected stator
P Pulse Stator connection for tachometer
R Relay Output to charge relays, etc
S Sense Battery Voltage sense wire

Where does the brown wire go from alternator?

The brown wire goes to the bulkhead and through up to the main cluster plug. If you had a cluster with a volt meter this wire would be used for that.

Can I run a wire from the alternator to the battery?

Attach a cable directly from the alternator output post to the positive side of the battery. This allows for full output from the alternator to the battery when heavy electrical demands are placed on the alternator.

What is B1+ and B2+ on alternator?

The B1+ and the B2+ are both charging terminals, one is larger than the other for which ever size cable you have, you only need one. It is a one wire self exciting, internally regulated alternator and I hooked up the positive battery post to the B1+ and it charges great.

What does the W mean on an alternator?

The W terminal generally outputs an unrectified AC voltage, the frequency of which is proportional to the engine speed.

What should alternator D+ voltage be?

The D+ signal wire is used as an on and off switch for these devices, its main purpose is to send a 12V+ signal to the device when the vehicle is running.

What happens if you hook up an alternator backwards?

Moderator. Looking at Amphi’s sticky thread about Burnt links and runaway starter shows the two links that usually blown. By hooking up the alternator backwards caused a very similar reverse current flow and there by burning out the same two links.

How much current is needed to excite an alternator?

Good numbers. Think in terms of field current, not voltage. It takes very little field current (probably less than 1/10 amp) for the alternator to bootstrap itself into operation.

What does R mean on alternator?

The “R” terminal or Relay terminal as it is sometimes called, provided some of the alternator’s output and was used to power electric tachometers, a dash light, hour meters, or other modern accessories. In some applications it was connected to the dash light to give notice if the alternator was failing to charge.

What is the difference between 1 wire and 3 wire alternator?

Striking a compromise between functionality and looks is a battle that can arise when it comes to choosing an alternator. While the 1-wire units offer clean and simple installation with minimally visible wiring, the OE-style 3-wire units can provide better electrical performance for the demands of your hot rod.

How do you hook up a 3 pin alternator?

How to Draw 3 Wire Alternator Wiring Diagram in EdrawMax

What happens if alternator is not grounded?

Poor ground connections are a cause of low charging output. There are positive and negative battery cable connections, the BAT+ power connection, and the engine ground strap. Overcharging can be caused by voltage dropping on the negative side.

Can you ground an alternator directly to the battery?

The alternator is mounted on the engine and the engine should have a ground strap to the frame. From the frame there is a ground strip to the battery. That’s a long way for a ground circuit. Works fine when the truck is new but after 30+ years you’ll have all kinds of corrosion on metal parts.

How do you ground a single wire alternator?

how to and why to ground your alternator

What is the brown wire on a voltage regulator?

The brown wire goes to the voltage light which I am replacing with a different kind of idiot light for voltage readings so this part doesnt matter. But this tells me the #4 VR pin is an alternator power output wire. However, the brown/white wire goes on to the ignition switch ‘A’ (accy?) terminal.

What is the brown wire on a Chevy alternator?

It’s the wire for the alternator light. The circuit provides the indicator light and it also helps to excite the alternator and initiate charging when the engine is started.

Does alternator wire need to be fused?

Fuses are installed to protect wires from an overload, meaning that the draw (amps) from the load (appliance) exceeds the capacity of the wire (the size or gauge). Under this premise, the only way an alternator needs a fuse is if either the battery or the alternator itself experiences a dead short.

Should I fuse my alternator?

I always fuse the output of the alternator for safety reasons. If the field in the alternator were to collapse it could potentially create a dead short. I always use a fuse rather than a fusible link because they are easier to change if need be.

Do I need a bigger alternator for two batteries?

A car alternator will be more than capable of charging two batteries. However you need to be more careful about connecting two batteries together if one is charged and the other is not.