The Nissan Path

Nissan Pathfinder LE 2006 gas v6.

Hi because I have charge warning light and brake light randomly come on and then randomly go away I performed battery / generator test using multimeter. Battery terminals and cables are thoroughly cleaned and tightened, also belt tension is OK.

Here's test results clearly showing the problem with charging / higher voltage. Perhaps I am dealing with bad voltage regulator (IC regulator)? Please give me an advice in what direction to proceed.

1ST TRY:
1) before start battery voltage 12.7V
2) starter cranking voltage 10.3V
3) after start voltage went up to 14.5V and then few seconds later dropped to 12.5V. Charge warning light and brake light stay on after start.
4) at increased RPM 2000 voltage went up to 14.5V then when RPM decreased to idle it stayed 14.5V. Charge warning light and brake light went out.

2ND TRY:
1) 12.8V before start
2) 10.6V while starter cranking
3) 12.6 after start engine idling. Charge warning light, brake light are on.
4) UNDER LOAD (headlights, radio, A/C, flashers are on) I hear high pitch noise coming from generator and then voltage went up to 16.7 - 18.3 volts.

Am I dealing with bad IC regulator? What direction should I take to further investigate the problem? Where is IC regulator located inside or outside alternator?

Thanks a lot! I appreciate any help. I need to drive on Thursday

Hey guys any additional thoughts will be appreciated!

Nissan Pathfinder LE 2006 v6 gas.

So I decided to give it another alternator output test. My first test is quoted below. This time I was unable to repeat the situation when charge warning and brake lights would come on or any other irregularities with voltage. This problem seems to occur intermittently and randomly and then it goes away. My guess I will need to wait until charge warning light comes on again to be able to pinpoint the problem.

MY MAIN CONCERN is that during the first test under load (headlights, radio, A/C, flashers are on) I heard high pitch wining coming from generator area and at the same time voltage on battery terminals went up to 16.7 - 18.3 volts.

Next I am going to follow charging system trouble diagnoses procedure, but I am afrait I won't be able to find anything until the problem occurs again.
Also original problem and symptoms were reported here:
http://www.thenissanpath.com/viewtopic.php?t=12833

1. Warmed up engine, engine bay.
2. Removed battery surface charge by turning headlights on for 2 minutes.
3. Took a battery terminals reading with multimeter -- 12.5V.
4. 10.6V while starter cranking.
5. Idling enginve 14.3V.
6. After idling and then increasing RPM to 2000 voltage dropped 13.2V.
7. Under load:
12.1V with turned on headlights, radio, A/C, flashers. After starting the engine voltage went up to 14.2V.
8. Checked negative " - " voltage drop. Under load 0.024V and no load 0.015V. (Did not check positive " + " yet).

alecsey wrote:Nissan Pathfinder LE 2006 gas v6.

Hi because I have charge warning light and brake light randomly come on and then randomly go away I performed battery / generator test using multimeter. Battery terminals and cables are thoroughly cleaned and tightened, also belt tension is OK.

Here's test results clearly showing the problem with charging / higher voltage. Perhaps I am dealing with bad voltage regulator (IC regulator)? Please give me an advice in what direction to proceed.

1ST TRY:
1) before start battery voltage 12.7V
2) starter cranking voltage 10.3V
3) after start voltage went up to 14.5V and then few seconds later dropped to 12.5V. Charge warning light and brake light stay on after start.
4) at increased RPM 2000 voltage went up to 14.5V then when RPM decreased to idle it stayed 14.5V. Charge warning light and brake light went out.
5) second time RPM increase to 2000, voltage dropped town to 13.17V.

2ND TRY:
1) 12.8V before start
2) 10.6V while starter cranking
3) 12.6 after start engine idling. Charge warning light, brake light are on.
4) UNDER LOAD (headlights, radio, A/C, flashers are on) I hear high pitch noise coming from generator and then voltage went up to 16.7 - 18.3 volts.

Am I dealing with bad IC regulator? What direction should I take to further investigate the problem? Where is IC regulator located inside or outside alternator?

Thanks a lot! I appreciate any help. I need to drive on Thursday