My charging circuit is not working. II have done all the easy things. Replaced Alt., Regulator and Battery. All are new not remanufactured. I tried to take as many thing as possible out of play I disconnected Blower motor, Ac, radio. I am at a complete loss any help will be appreciated. Thanks much Paul Working on ; 67 Firebird 400 Conv. w/air
If that fusible link is intact check the fusible link between the connector block, on the rad support just in front of the battery, and the battery + post. Start the car and check the voltage at the battery then check the voltage between the BATT [output] terminal at the alternator and a ground on the engine or body. That info will lead us to the possible problem. If the battery has 12 volts and the alternator has 14 we know the problem is between the alternator and the battery, if they both have 12 volts it's most likely in the wiring since you've replaced the components. Does the gen warning light come on when you turn on the ignition switch?
The wire that goes from the spliced buss near the horn relay to the orange fusible link and the #3 terminal at the voltage relay is the voltage sense wire. It senses the voltage at the splice and regulates the alternators output to keep the voltage at 14+. The brown wire that goes from the ignition switch to the #4 terminal turns the charging system off and on. If there is not 12 volts to this terminal the system will not work. With the car shut off, pull the connector off the voltage regulator and test for voltage at the terminal that connects to #4 on the regulator, it should be 0 volts. Turn the ignition key on and check the voltage it should be battery voltage. If you don't have 12 or so volts at #4 when the key is on there is a break in the circuit or a faulty ignition switch. Could be a faulty regulator connection or a break in the two wires from the F and 2 terminals at the regulator to the plug in the alternator.
OK, All fusaable links are good. Bat. 12v, Alt output 12v. I have gauges no light. When key is on the gauge will discharge very slightly. I have power on both sides of the horn relay. I did bypass the regulator with a jumper from F to 3 with no change in Alt. amp output Voltage Regulator 3 has power all the time 4 power when key is on I have a condenser connected to the back of the regulator. I don't think this has anything to do with the problem ? Does the relay on the firewall next to the power break booster have anything to do with this. When I pull the Ignition switch what am I looking for? Thanks everyone for your help. Paul
Paul, My memory isn't as good as it used to be but, seems to me if you give the 'F' field connector at the alternator 12 volts you should get full output. If you have connected 12 volt supply to the F connector at the alternator and you didn't get a jump in voltage your new alternator may not be working. I wish I could help more. Al
Oh yea, that condensor on the back of the regulator is to reduce radio interference. Looks like your wiring is all good. If I understand what you've been saying so far, your alternator isn't charging and you do not have a gen warning light but an amp meter, when you turn on the ignition switch you have a slight discharge on your meter, when you start and run your car you have a slight discharge on your meter, wiring between your battery and alternator is good, you have constant 12 volts at #3 on regulator, you have switched +12 volts at the #4 terminal, you jumped the field circuit to 12 volts and did not get a spike in alternator output. When you jumped the F terminal to battery voltage your Alternator should have spiked up to 15 or so volts, if it didn't your alternator is most likely defective. Maybe take it off and take it to a parts store who can check it. The switched +12 volts through your meter to the #4 terminal supplies power to the regulator which directs this power to the field depending on what the voltage is at #3. after the alternator starts to put out the regulator takes the power from the alternator via the diode trio and uses that voltage to charge the field. At that time the gen light will go out or in your case the meter will no longer show a discharge. It should show a charge as long as the alternator is puting out a higher voltage than the battery. I wonder if you bought a regulator for use with a gen light and not one used with a meter. If in fact they are different. Seems to me when using an ammeter and not a light the wires to the #4 terminal from the switch and from the alternator 1 are tied together. I'm just going by memory and that may not be the case.
Well here is the latest. I ran a ground from the Bat to engine and body to assure that was not the cause but no luck. Then I pulled all the fuses and disconnected headlight switch, blower and AC comp.. I know I'm throwing sh*t at the wall but I'm running out of ideas. I have a hard time thinking it's the Alt. What are the chances of getting two bad Alt. in a row. The first was rebuilt but the second was new. That said I'll have to pull the new one and have it tested. Thanks everyone for your help. Paul
Paul, Did you check the continuity between the F and 2 terminals that plug onto the regulator and the plug at the alternator? Maybe everything is good but the alternator isn't really connected to the regulator. Al
Bluebird428 What am I checking for and what should I get with your suggested test. Since it was OK for years and then just stoped working, you may be on to something . Thanks for your input. Paul
Get a multimeter with a continuity tester. Disconnect the two wire plug from the alternator, disconnect the four wire plug from the regulator. Place one tester probe on the connector that connects to the F terminal and the other probe on the F terminal of the two wire plug, the meter should show continuity. Do the same with the wire that goes to the terminal marked 2 on the regulator and the other wire in the two wire alternator plug. There has to be continuity between the four wire plug and the two wire plug in order for the regulator to send current to the alternator field. If that checks out OK get your regulator and alternator checked at the parts store.
