You'll have to reconnect it to do this. I just went out and unplugged my voltage regulator and grounded the " I " terminal on the plug and the " alt " light does come on when I turn on the ignition. I did it with a direct jumper. I said to use the test light cause I wasn't sure, but I am now! You must have power to one side of the alt light when the ignition is on. I'm not sure of the colors of the wires to the cluster, but you should have continuity ( no resistance ) between the other side of the bulb to the " I " terminal wire in the regulator plug also. I hope this helps!
Yes. Hook the battery back up Unplug the I terminal from the voltage regulator Hook up your volt meter to measure the voltage across the battery Start the engine With the engine running, take a jumper wire and connect one end to the Positive battery terminal and touch the other end to the I terminal of the voltage regulator (do not let it touch any other metal, ground, etc) Read the voltmeter to see if your alternator is charging Remove the jumper wire Read the voltmeter again Turn off the engine Report back with your findings
im a little confused, by jumper wire do you mean a jumper cable, and how do i touch it the the i terminal with almost no room between the body and regulator? thanks for the help everyone!
Not a jumper cable, that is a VERY large jumper wire. I mean like some old speaker cable. Or some other 18AWG wire you have laying around. To touch the I terminal, you may have to get creative. Maybe try and get a female spade connector to slide over the male I terminal, then crimp your jumper wire onto that.
I had a similar problem awhile back, turns out the fusible link between the alternator and the battery popped. It's in the large wire running from the alternator to the battery. You can test the alternator simply by using a non magnetic screw driver and using it to touch the larger center steel cover on the rear of the alternator, if it's charging, this part will be magnetized and attract the screw driver tip.
Ok, what you did was provide a 12V+ source to the exciter circuit while the engine was running. That means I don't think the problem is in the ignition switch -> charging indicator circuit. Next we need to rule out the feeds to the alternator and regulator. Now do this: Unplug the A terminal Using your volt meter, connect the black lead to the battery Negative terminal, then touch the red lead to the A terminal connector (the wire side, not the regulator side) Read the voltage, write it down Plug the A terminal back in Then, using your voltmeter, with the black lead still connected to the battery Negative terminal, touch the red lead to the alternator output stud (on the back of the alternator) Read the voltage, write it down return with your findings While you are at it, we can double verify the results of the I terminal test by doing this: Unplug the I terminal connector Connect the black lead of your voltmeter to the battery Negative terminal then turn the key ON/RUN (but do not start the engine) Take the volt meter red lead and touch the I terminal connector (wire side, not the regulator side) Read and write down the voltage It should read the same voltage as the battery voltage (sounds to be around 10V from your statement) You are doing fine and hopefully learning a little along the way.
By the way, you do have the regulator installed to the inner fender, correct? The ground for the regulator is achieved through its case being screwed to the chassis.
Ok, so when I tested the a terminal and alt output I got 12.02v. the battery said 10v yesterday so i.checked the battery and got 12.2v but when I turned the ignition on to check the I terminal the battery went back down to 10. But the I terminal tested the same as the battery, 10v. The battery stays at 12v when the ignition is off but goes down to 10v when the ignition is on and goes back to 12 when ignition is turned off again. I really appreciate all the help.
Ok, that is interesting about the battery voltage. One more test, then I think it will be time to replace the voltage regulator. Remove the battery wire from the alternator output terminal Check the battery voltage, record the reading Turn the ignition ON/RUN Check the battery voltage, record the reading report your results These tests check whether the alternator is pulling a large load on the battery. In the end, I think you will end up replacing the voltage regulator. Here is what the tests you have done so far have determined: The I terminal is getting voltage to excite the alternator. Even if suppled voltage, the exciter circuit does not begin charging The A terminal and alternator output terminal have a good connection to the battery. All that is left is the voltage regulator itself, (based on the fact that you said the alternator is GOOD). If you buy a new voltage regulator, buy a good one. Motorcraft, etc. People have been known to have problems with the cheap ones.
forgot to disconnect the negative battery terminal before i removed the alternator output and got a nice little shock. with the alt output disconnected and the ignition off the battery tested 11.8v and with the ignition on it tested 8.7v. the alternator being good is just what the guy at advanced auto said.
I'm with Resto. Either the voltage regulator is bad causing the alternator to act as a load or the alternator is bad. If they tested the alternator at Autozone, then I would say replace the voltage regulator first.
Ken, charge your battery. It should be 12.6V, or right around that. The reason your voltage drops so much when the ignition is on is the ignition coil is energized with the ignition on. It draws a fair amount of current + your battery is discharged. The shock you got is actually a good thing because it means the alternator output is a complete circuit to the battery. After you charge your battery, connect your voltmeter to the battery, start the engine and with the plug removed from the voltage regulator connect the " F " terminal to the + side of the battery with a small jumper wire. The voltage should instantly start to rise. Don't let it rise above 15.5V! If it does rise, the alternator is working and like was suggested, the regulator is probably bad.
