What Voltage Should Negative Side of Coil Read When at Idle 1970 Challenger

March 08, 2022 Post a Comment

Dan Ferrell writes virtually practice-it-yourself auto maintenance and repair. He has certifications in automation and control applied science.

Alternator, voltage regulator and other components.

Photograph in the Public Domain.

Symptoms of a bad voltage regulator may include:

Loftier voltage output
Low voltage output, sometimes
No voltage output
Lights dim or flicker
Faulty loftier-beam headlamp bulbs
Engine working erratically (weak or flickering ignition organisation)
Calculation water to the battery oftentimes
Growing corrosion around bombardment terminals and summit
Dead battery
Battery or cheque engine light indicator lit on dashboard

Keep in heed that some of these symptoms may come from loose or corroded charging system connections.

Therefore, make sure to check for:

clean and tight battery connections
expert bombardment cables
good engine and chassis ground connections and wires
battery clean and in good operating condition (have information technology tested, if necessary)
Drive or serpentine belt not worn and with proper tension.

These preliminary checks will assistance yous eliminate the about common charging organisation problems.


Index
I. What Does a Voltage Regulator Exercise?
II. Voltage Regulator Test
ane. Checking Wires Using Voltage Drop
2. Voltage Regulator Bypass Test
iii. Voltage Regulator Aligning
four. Testing a Contact-point Voltage Regulator
Iii. Voltage Regulator Replacement

Check the battery and charging circuit to make sure they are not interfering with charging system operation. — Check the bombardment and charging circuit to brand sure they are non interfering with charging system operation.

Photo in the Public Domain.

I. What Does a Voltage Regulator Do?

Basically, the voltage regulator controls field current through the rotor, inside the alternator, in club to control alternator output.

Without a voltage regulator, an alternator may put out up to 250 volts. This is enough to destroy the car's battery and electrical organisation.

The voltage regulator is unremarkably found inside or on the back of the alternator case. Increasingly, though, late-model vehicle accept the engine control module (ECM) regulating alternator voltage output through a special circuit.

Older models used an electro-mechanical, external voltage regulator, mounted somewhere in the engine compartment.

On a estimator controlled charging system, the electronic or powertrain command module can monitor system functioning, cutting off charging output if voltage levels are too loftier, and trigger diagnostic trouble codes. This is part of a fail-prophylactic-excursion in the computer, and tin can profoundly help you diagnose system bug and draw potential faults.

II. Voltage Regulator Test

Charging voltage can vary between 13.5 and 14.8 volts, depending on ambient temperature.

In a nice, 70 F (21 C) day, you lot can expect a voltage regulator charging your car'south battery at about xiv.2 volts. And the higher the temperature, the lower the charging voltage.

This test is a simple procedure to check alternator voltage regulator output. You need a digital multimeter for this exam.

Fix the parking brake and shift the transmission to Neutral (manual) or Park (automatic).
Prepare your multimeter to DC Voltage and select the 20 Volts in the scale.
Connect the meter's blood-red lead to the battery'due south positive (+) post and the meter'south black lead to the bombardment's negative (-) mail service.
Notice the open-circuit voltage of the bombardment. Your battery should exist at about 12.6 volts, 12.4 volts minimum; otherwise, charge the battery and continue with this test.
Now, ask an assistant to start the engine and run information technology at 1500 rpm.
Take a note of your voltmeter reading.

A expert output voltage should be virtually two volts higher than your battery open-circuit voltage. Consult your vehicle repair manual, if necessary, to check the correct specifications for your item model.

If you lot noticed an output voltage reading beneath thirteen volts right after starting the engine, there could exist a charging organisation problem. Deport a voltage driblet test equally described in the following subsection 1. Checking Wires Using Voltage Drop.
If the output voltage reading is 16 volts or higher, there's an overcharging problem. This ordinarily indicates a bad voltage regulator.
If voltage seems to fluctuate during your test, switch your voltmeter to the AC voltage scale and accept another output voltage reading with the engine still running.
- This time, connect your meter'southward cerise lead to the B+ terminal on the back of the alternator, and the meter's black lead to battery negative (-).
- Usually, the presence of 0.25 AC volts means a leaking diode that requires replacing the alternator. But some manufacturers recommend replacing the alternator if 0.50 Air conditioning volts is detected.
- Notwithstanding, if you have noticed engine functioning issues, this might be the problem. Consult your vehicle repair manual for adequate diode leak rate, if necessary.

If your output voltage is within specifications, continue with this exam:

With the engine running, increase engine speed to 2000 rpm.
Turn on the headlights, Ac, defogger, and other high current accessories you may have.
Take a note of your voltmeter reading.

The voltage output reading should be about 0.v volts higher than your bombardment's open excursion voltage.

Most voltage regulators are calibrated to output between 13.5 and xv.5 charging volts on a fully charged bombardment at normal temperature with no accessories or lights on. Consult the specifications in your vehicle repair manual for your particular application.

Proceed in heed that a worn or loose drive belt and other vehicle operating conditions like loftier temperatures can affect how the voltage regulator operates.

When your test shows a steady or intermittent high or depression voltage output, the voltage regulator is perchance bad. Most voltage regulators fail by allowing a high voltage output, though. However, before going any farther, cheque that all the connections to the alternator and battery are good and clean as described in the adjacent section.

1. Checking Wires Using Voltage Drop

A quick way to examine the wires and connections in the charging system is to check for voltage drops.

Set your voltmeter to 2 volts.
Start the engine and let information technology idle.
Mensurate for voltage across individual wires and connections in the charging system.
If in that location's voltage over 0.ii volts in whatever wire or connection, check for corroded, damaged or loose wires.
When fixing wires and connections, aim for a voltage drop of less than 0.1 volts or 0.

This post on charging organisation voltage drop tests walks you in more particular through the steps. Pay special attention to the basis side of the charging arrangement which tin crusade trouble for the voltage regulator.

If the charging excursion connections are good, go along with the post-obit tests. Y'all tin check whether your voltage regulator is at error through a regulator bypass exam, as described in the following section.

The following video gives you a charging organisation check overview that you tin follow too to test your charging organisation, if necessary.

2. Voltage Regulator Bypass Examination

On many alternators (except those with calculator voltage regulation), you lot tin bypass the voltage regulator to test whether your voltage regulator or another component (alternator or charging circuit) is at fault.

There could exist several ways to bypass the voltage regulator, depending on the charging arrangement configuration for your item vehicle model. Your voltage regulator may be connected to the power side of the circuit (type-B circuit) or the ground side (type-A circuit). Consult your repair manual.

If the rear of your alternator has a 'exam tab', yous need to brusk this tab to the alternator frame using a screwdriver while checking voltage output at the battery with the engine running.
On other systems, you may need to connect the battery and field terminals using a jumper wire while checking voltage output at the bombardment with the engine running.
If your car'due south charging system is controlled through the figurer, y'all may need a scan tool to check voltage regulation.

On modern Chrysler vehicles, virtually probable the figurer regulates alternator output voltage. Depending on its particular configuration, you lot may test charging output by grounding the corresponding field terminal, or applying battery voltage to the appropriate terminal (on B-excursion types, 2002 and newer).

Follow these precautions:

During your examination, keep all electric accessories off before starting the engine.
Disconnect the jumper wires once your digital multimeter reads charging voltage.
Turn off the engine.

Consult the vehicle repair transmission for your item model to carry this test, if necessary.

When the voltage regulator is bypassed, y'all should encounter maximum voltage output.
If voltage output remains at a normal level, virtually probable the voltage regulator is faulty.
If voltage output remains at the same level (depression, for case) as in your initial test (Section 2, step 6), most likely yous have a faulty alternator.

The adjacent video shows yous how to test an external voltage regulator and how to bypass information technology.

3. Voltage Regulator Aligning

Some alternators with an old configuration allow adjusting of the voltage regulator. On these units, you can notice a small adjusting spiral on the voltage regulator.

Connect your voltmeter beyond the bombardment posts.
Set the Parking brake.
Shift the transmission to Neutral (manual) or to Park (automatic).
Start the engine and let it idle. Turn off whatever accessories, if necessary.
Check battery charging voltage.
Plough the adjusting screw using a modest screwdriver to arrange charging voltage to specifications.

Refer to your vehicle repair transmission to make sure y'all accept an adjustable voltage regulator, locate the adjusting screw, and set voltage output to specifications.

iv. Testing a Contact-bespeak Voltage Regulator

Former blazon DC generators and early vehicle charging systems used a contact-point blazon voltage regulator. Basically, it consisted of a coil, a set of points and resistors to control alternator voltage and current output. These regulators were replaced by electronic or solid-state voltage regulators.

All the same, there might exist some vehicles on the road today fitted with this blazon of regulator.

Usually, the contact points in the regulator are the ones to cause problem later on many miles of service due to habiliment or pitting.

To repair a contact-indicate voltage regulator:

File, test and suit the regulator points, as necessary.
If still, voltage output is out of specifications, replace the regulator.

Refer to the repair transmission for your particular vehicle brand and model.

If necessary, replace the voltage regulator or install a new alternator. — If necessary, supersede the voltage regulator or install a new alternator.

Photo courtesy of Phasmatisnox on Wikipedia.

3. Voltage Regulator Replacement

To supercede it, remove the voltage regulator from the back, or inside, of the alternator. Consult your vehicle repair manual for the procedure for your particular model.

If you don't have the transmission yet, you can purchase a relatively cheap copy online through Amazon. Haynes manuals come with step-by-footstep procedures for many maintenance, troubleshooting and component replacement projects you can do at abode. And then you'll recoup your small investment before long.

Some vehicle models use alternators with internal voltage regulation. You'll need to replace the alternator, if voltage regulation has failed.

The same goes for computer-controlled voltage regulation. When the voltage-regulator circuit fails, most likely you'll need to replace the Powertrain Command Module (PCM).

Probably your voltage regulator passed the tests. Still, you withal may doubtable a problem in the system. In this case, this other postal service will aid you check the charging system in your car.

This content is accurate and true to the best of the author'southward knowledge and is non meant to substitute for formal and individualized advice from a qualified professional.

Questions & Answers

Question: When you wrote, "Without a voltage regulator, an alternator may put out upwards to 250 volts," is that referring to when a car is on the highway or a racecourse?

Answer: Information technology was referring to how much the alternator may put out if it didn't have a regulator.

Question: Is there a more simple solution for the "over voltage" trouble from the alternator regulator? For example, can we non put another filter (voltage regulator) after the alternator to continue the voltage between 12 to 14.5 volts?

Reply: If the original internal regulator failed, usually y'all tin can replace the unit of measurement with an OEM part. Information technology's calibrated for your specific application. External regulators require dissimilar wiring set up to work.

defilippoalmou1979.blogspot.com

Source: https://axleaddict.com/auto-repair/Alternator-Voltage-Regulator-Test