Car Voltage Regulator Connection

have the alternator checked. The voltage regulator should be a discrete unit .....see link below
Toyota Hilux Hiace alternator 36 months warranty


the voltage regulator is connected directly to the alternator, it is pictured in above link

The voltage regulator is integrated into the alternator. You need to replace the alternator as a unit. If the replacement alternator is supplied with an electrical pigtail, DO NOT get lazy and simply hook up the existing connector to the alternator. These connectors get hot and break down, resulting in the failure of the regulator. That is why the new connector is provided. You will void your alternator warranty and have early unit failure if you do not cut off the old connect and splice in the new one. If you are not capable of doing that, get a professional or someone who is capable to do it for you.

measure battery voltage while engine running good is 13V to 14V then over charging is 17V to 18V DC
if ok battery gauge could be defect
if not ok then look for stuck pulley on alternator belt by removing the belt and turn all pulley free.

hope it help

In some brand of alternators the regulator and brushes are an integral part and it is a matter of removing 2 screws and lifting out the part. On others the regulator is entirely separate unit located some where else on the vehicle. The voltage of 15.3 is on the upper end of the charge rate but it would be acceptable . Nominal voltage for a regulator is 14.5 to 15.5 volts. Understand that a battery is actually 13.2 volts not 12 volts and you need 14 volts for the battery to charge effectively. The higher the voltage the higher the amperage to run everything so if your alternator regulator is set at 14.5 volts then the max amps of the alternator would not be reached and if you have a current draw to run everything that is more than the output of the alternator then the battery will eventually go flat. Find yourself a reputable auto electrician and discuss the problem with him not a local mechanic

Due to the nature of the battery technology used with vehicles the alternator is mostly incapable of charging the battery. The car alternator is designed to keep a fully charged battery fully charged and to provide all the power for the car equipment.

The alternator charge rate is regulated by a voltage regulator. Because the alternator output is connected to the battery, the alternator and battery voltage will be the same and the voltage regulator monitors that voltage.

The lower the battery voltage the more output the alternator will produce in order to correct the situation but because a lead acid battery has a high internal resistance to accepting a charge the terminal voltage will quickly rise to the alternator regulated voltage and fool the alternator into thinking the battery is fully charged when the output will drop to the order of just a couple of amps.

Switch on the headlights or a similar load that will lower the battery voltage and the alternator will increase it's output again - but only by the amount of current the headlamps or other load is consuming.
It matters not what the alternator rated maximum output is, it is designed to provide only the necessary current and no more.

The only time an alternator should ever need to produce maximum output is when on a dedicated testbed and then only for a short duration to avoid damaging the unit. Testing the current output on a modern vehicle is not recommended except for the regulated voltage testing and a rule-of-thumb output test where all equipment is switched on and the engine speed raised while the battery voltage is monitored.

Most modern alternators use an internal voltage regulator but a few systems use a separate voltage regulator. No alternator rebuild would be complete without a regulator test and probably a new or replacement regulator, which is where the majority of charging system problems are, or the brush gear.
Assuming the wiring is ok, no alternator should suffer any harm if the voltage regulator and auxilliary diodes (if fitted) are in good order though fitting a defective or a discharged battery can cause it to overheat and be damaged.

The alternator usually just about stops producing an output when the battery voltage is in the region of 14.5/14.8 volts.
Your description indicates the voltage regulator is not working correctly - unless 40 amps was being consumed by the car equipment the alternator should not have been producing 40 amps.. I suggest you also have your battery tested

You have a short or a bad voltage regulator. Check your battery connections. Not just on the battery, check the wires all the way to the connection points to ensure there are no worn insulation where the positive wires could possibly be grounding out. Get the Haynes Repair manual on your vehicle so you can locate the voltage regulator. Typically this is part of the alternator but in several VW vehicles I have had and worked on the voltage regulator is in a separate location. Test the voltage regulator according to the manual.

VOLTAGE REGULATOR IS LOCATED BEHIND BATTERY.YOU PROBABLY MIGHT HAVE TO REMOVE BATTERY TO REMOVE THE VOLTAGE REGULATOR.

ck your alternator if you have one large white wire and two smaller dark wires you've got an internal regulator the entire alternator needs to be replaced if bad

a simple voltmeter you can still buy at radio shack will tell you in about 30 seconds

set meter for dc volts 25 volt scale place red probe on battery positive and black probe on battery negative note reading on voltmeter (11 to 12 volts) start truck/car at idle reprobe battery same as before volts should come to about 12/13 have someone give a slight throttle to engine volts should come to 13.8 volts and stay there never going over this if any volt reading was not as described Yep your voltage regulator/alternator is bad

You may have a voltage drop in the battery feed to the Alternator through the fuse link and into the battery. Check the charge rate at the battery feed on the Alternator, it should be at least 13.8 volts, if it is, locate the fuse link and check it there on both sides of the link, if its still good, follow the cable back to the battery checking the voltage as you go. If you find that the voltage suddenly drops across a connection or the fuse link, remove and clean the connection or replace it if possible. If the voltage at the back of the Alternator is less then 13 volts, then the new Alternator may be faulty. If the voltage is higher then 15 volts, then the Battery feed to the Alternator is bad and MUST be fixed. Check these voltages with the engine running but watch out for moving parts ( fans etc). If you think the battery feed to the Alternator is bad, shut the engine down and recheck the voltage at the Alternator, it should be at least the same as it is across the battery. If there is no power to the Alt when the engine is off, start at the fuse link, checking for voltage and trace back to the alt until you lose the reading. If you get no voltage at the fuse link, track it back to the battery. The voltages at the battery and Alternator should be the same or only have a difference of half a volt, any more and you need to locate and fix the bad connection. DO NOT run the Alternator without the load of the battery for extended periods as this will damage the Alternator. The Alt needs the internal resistance of the battery to function correctly. If the voltages from the battery to the alt are correct, check the regulator wiring. If memory serves, there are two small wires to the alt which are in a small plug into the alt and one thick cable which connects to a bolt on the alt. The thick cable is the battery feed, the two small cables are the regulator feeds. One small cable operates the warning lamp in the dash cluster and the other is another battery feed which gives the regulator an indication of the charge rate AT THE BATTERY so if this one is missing the regulator will also cut out. The warning lamp wire serves as an indication to the regulator that the ignition is turned on and makes the alternator charge. This lamp should be on with ignition on but engine NOT running and should go out when you start the engine. If this lamp does not light up at all, suspect a broken or missing warning lamp connection or faulty regulator.A blown warning lamp bulb will also prevent the alt from working, this is because the bulb is fed with power and is grounded at the alt through the regulator and exciter diodes, feeding the regulator with power until the engine starts, then the alternator output essentially puts power to both sides of the diodes causing the lamp to extinguish. A diode is a one way valve for electricity and the regulator is inside the alt. If you suspect a faulty alt or regulator, remove them and have them checked by an autoelectrician. Unless you know what you are doing, DO NOT attempt to disassemble the alt as you can cause catastrophic damage and have to purchase a replacement alt. You may also void any warranty by disassembling the alt.. Undertake these tests and if you have any questions, email me here: [email protected]
Dave.

Joe, there is no longer a regulator on this car as we would know it to be. The ecm is now also resposible for telling the alt when to turn on and off. This was done in order for the alt to be turned on and off in conjunction with the other loads and engine speed in order to be more efficiant in the long run. So from what I read here, you either have a bad wire somewhere or your ecm is toast. Replacing lights-unless for some reason the wires were cut(doubtfull) would have no effect on the alt.