Alternator problems?

S

SuperDad

Registered User
I just replaced my Power Steering pump & when I drive the car the battery drains rapidly. I think the alternator may be shot! Can I test it myself, without bringing it down to the local auto part store? All the connections on the alt. are good:rolleyes:
 
Either the alterrnator is bad or the feedback wire is disconnected. Can you confirm the feedback wire is bolted to the back of the alternator?
 
Here is a test procedure to follow :

Step 1. Ensure battery is fully charged. After charging, check battery voltage. Should be in the range of 12.1 to 12.7 volts. This is your base voltage.

Step 2. Confirm battery connections are good, all connections and the battery posts are clean, and all connections are tight. Measure ground resistance between the block and battery ground post to ensure good connection.

Step 3. Check alternator connections are tight and have good contact. There is a three wire pigtail to the alternator and a feed back wire with a loop type lug connector that is attached by a nut to the stud on the back of the alternator. Measure resistance between the feedback wire and the positive battery post to ensure good connection.

Step 3. Turn off all accessories (turn off daytime running lights by engaging E-brake) and start the car and let run at idle. Check the voltage. You should have ~1.5-2 volts over the base.

Step 4. Turn blower motor on high, turn on high beam headlights. Increase engine speed to 2000 RPM and check the voltage. The voltage should be a minimum of .5v above the base battery voltage and a maximum of 2v over the base voltage.

Step 5. If voltage is below min, disconnect pigtail and check circuits I & A as outlined (diagram below):
Step 5a : connect jumper wire from I-terminal to battery ground. Turn key to run, but do not start. The charge indicator warning light should come on. If not, cehck bulb, if bulb is good, there is an open in the I circuit. If light dos come on proceed to 5b
Step 5b : Connect voltmeter negative lead to negative batt post. Connct positive lead to A-terminal. Battery base voltage should be present. If not, there is an open in the A-circuit.

diagram for pigtail terminals :
W W W
____________
/ \
| [A] |
| |
-----------------
CLIP SIDE


Step 6. If you still have below min voltage, and ground, feedback, I circuit, a-circuit wiring is all good, you need an alternator.


While there is the possibility that the alt coincidently failed right after you finished the pump, it is unlikely. Since you had the alt disconnected to do the ps pump, there is llikely a problem with something being connected properly and you will likely find your problem in steps 1 or 2. Let me know how it works out.
 
Diagram didn't work so great. At any rate, if you disconnect the three wire pigtail and are looking at the female connections with the clip to hold it in place facing down, the I is on the left and the A terminal is on the right.
 
hodian said:
Here is a test procedure to follow :

Step 1. Ensure battery is fully charged. After charging, check battery voltage. Should be in the range of 12.1 to 12.7 volts. This is your base voltage.

Step 2. Confirm battery connections are good, all connections and the battery posts are clean, and all connections are tight. Measure ground resistance between the block and battery ground post to ensure good connection.

Step 3. Check alternator connections are tight and have good contact. There is a three wire pigtail to the alternator and a feed back wire with a loop type lug connector that is attached by a nut to the stud on the back of the alternator. Measure resistance between the feedback wire and the positive battery post to ensure good connection.

Step 3. Turn off all accessories (turn off daytime running lights by engaging E-brake) and start the car and let run at idle. Check the voltage. You should have ~1.5-2 volts over the base.

Step 4. Turn blower motor on high, turn on high beam headlights. Increase engine speed to 2000 RPM and check the voltage. The voltage should be a minimum of .5v above the base battery voltage and a maximum of 2v over the base voltage.

Step 5. If voltage is below min, disconnect pigtail and check circuits I & A as outlined (diagram below):
Step 5a : connect jumper wire from I-terminal to battery ground. Turn key to run, but do not start. The charge indicator warning light should come on. If not, cehck bulb, if bulb is good, there is an open in the I circuit. If light dos come on proceed to 5b
Step 5b : Connect voltmeter negative lead to negative batt post. Connct positive lead to A-terminal. Battery base voltage should be present. If not, there is an open in the A-circuit.

diagram for pigtail terminals :
W W W
____________
/ \
| [A] |
| |
-----------------
CLIP SIDE


Step 6. If you still have below min voltage, and ground, feedback, I circuit, a-circuit wiring is all good, you need an alternator.


While there is the possibility that the alt coincidently failed right after you finished the pump, it is unlikely. Since you had the alt disconnected to do the ps pump, there is llikely a problem with something being connected properly and you will likely find your problem in steps 1 or 2. Let me know how it works out.
Click to expand...



Wow, you just said a mouthful there.:eek:
I am so fried from work, I'll have to read that a dozen times before any of it sinks in. I am 99% sure all of the connections are tight. I will have to go in there this weekend & scope around a bit more. The battery tested good when I brought it in to Auto Zone. I can tell the car is running strictly off the battery. The battery light on the dash flickers on & off while I drive. It runs fine until I shut it off & try to restart it, then she's dead. Is there a fuse inline somewhere that I could have popped, while I was changing the P/S Pump?
 
Do the tests in step 5. That will tell you if there is something burned out in the wiring. Also check continuity between the feedback wire and the postive battery post.
 
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