Hey everyone. The help I'm seeking from any expert here unfortunately requires some detail to explain. I'm so sorry this is a long post!

2005 SE 105,000 miles.

So, I had $5,000 worth of work done at my local Nissan Dealership, and after picking it up I now have a completely different problem! I think the new problem is charging-system-related.

Before I bring it in to them, I've been trying to get an idea if they caused the problem or not. So, I'll detail the new problem first and then list the work they did.

My new issue: After 2,000 RPM (roughly), my "Brake" and "Battery" lights flicker until I depress the gas pedal. The higher the RPM gets (like gunning it from a tollbooth), it will go as far as a quick loss of power and then a "jolting" return of power. Pretty scary the first time it happened. At the higher RPM, my aftermarket Amp will also cut out, and I've seen my HID fog lights flicker off then on once.

The work they did:

Not only did they replace brake pads, rotors, and rear calipers, but I also needed a new ABS Actuator and rear ABS sensor ($2,100 just for that! ouch!).
In addition to the brake repairs, I also needed chain guides and tensioner assembly's as well as two differently priced Camshaft chains.

Next, they replaced a valve assy solenoid "VIAS Solenoid". I'm really wondering if while all the work was done under the hood, the tech screwed up wiring something, or shorted something, etc. Although the car was previously pretty screwed up ( I also replaced a cam sensor myself before the other work), this new issue was no where to be found.

Tested the charging system as best I could with a DMM, and the alternator is fully charging the system. I put on EVERYTHING, lights, fan, 500 watt amp bumping, all my little LEDs I have throughout the car...and the voltage remained consistent. No lights flickering at all! What I did see is when parked and raising the RPMs to the 2000-3000 range, the voltage shot up to the 15's. I don't know if that's normal to be honest.

I have a strong car audio/electronics background, but I've never been exposed to alternator issues like this. I'm wondering if the voltage regulator is fried? Again, I'm hoping it may be a simple fix. I don't want to bring it in and have them tell me I need a new alternator, when they could've potentially caused the problem.

I stopped by the day after I picked the car up and went for a quick drive with the tech that did the work, and he said he didn't recognize the issue at all, which was a giant red flag for me. They said just to drop it off, etc. I remember the tech advisor saying the tech that did the work had 10 years Nissan experience...sounds fishy to me.

So, the real question is, is it a possibility that a mistake in the type of work done could cause this problem? Or was this just horrible timing and I need my alternator replaced? Any advice, or suggestions on any other testing I could do on my own would be such a great help. I really want to monitor the voltage while driving but I held off because I'm a little wary of running a hot wire open wire to my DMM. I'm pretty desperate for help, as I really don't have the money for an alternator.

If you made it this far, thank you so much! I appreciate it.

 

I can feel your pain, especially in the wallet. Since none of the repairs that you had done have any bearing on the alternator and or charging system per say, but some sort of accidental slip by the technician is a possibility. But proving something like that may have happened is next to impossible. And it may also be a case of unfortunate timing.

As far as diagnosing the charging/alternator problem, you have pretty much done everything the average owner can do. And the one voltage reading you got pretty much says what the problem is - the alternator has taken a dump. The alternator voltage is usually in the 14.1 - 14.2 volt range - never ever in the 15 volts. More specifically, the voltage regulator has failed. Being internal to the alternator, the alternator will have to be removed. But finding a place that has the voltage regulator printed circuit board may not be that easy.

With my sympathies to your wallet, I don't recommend replacing the voltage regulator without testing the rectifying diodes. One of them may have opened up, creating a heavy workload on the regulator. Just get another alternator, it's easier.

 

Thanks for such an awesome response. I appreciate it. I swear I searched the internet for a proper voltage reading at a higher RPM and couldn't find a specific 6th gen answer anywhere. I appreciate that alone!

It will probably take me a couple months to save for a new alternator, and although I'm probably handy enough to replace it myself while following proper instructions, I don't have a real jack or jack stands.

Today I'm going to check all the grounds I can just to make sure they're secure. That I think is my real last ditch effort to see if it is something other than the VR. Thank you for confirming my worst case scenario..bummer.

I went to just answer and asked a Subi tech, and he said just like you that it would be impossible to prove the Nissan tech had any fault. They would simply say it was bad timing and I need a new alternator.

Do you think my car is still safe to drive for a couple more months? I also have a bigger amp that I was going to install, a 1000 RMS watt, but my gut says to hold off until the new alternator is installed. Thanks again Dennis!

Slay

 

You have a bad alternator. To keep driving the car for a couple of month with it will be unpredictable. The alternator might totally fail at any time. However, in your specific case with the voltage level shooting up to 15+ volts, my advice is to not drive the car at all. The higher voltage will cause other electrical devices to weaken and fail. Your lights, radio and climate controls are the most susceptible.

Since money is tight, what you may want to consider is getting an alternator from the junkyard. It will be considerably less money than a new one, especially if you go to a pick-and-pull junkyard where you remove it from the car yourself.

Your sound system amplifier is also a concern to me. A 1000 watt amp will need more power than the standard 110 amp Nissan alternator can provide. When the amp is hitting max power (1000 watts), it is pulling something like 80 amps from the alternator. The stock alternator does not have very much reserve power so it cannot keep up with the demand the amp will put on it. The car battery will have to make up the difference.

So get your self a junkyard alternator for the short term. Save up your money and get a 250 (or more) amp alternator so you can power the sound system properly.

 

Thank you so much. Such an awesome response. The issue stopped happening. Ive spent countless hours rewired everything I've installed in the car. I am still interested in a upgrade alternator, as one day I would like to upgrade to a MX-110 amp to push 1000 RMS. I'm pretty sure I'll need that upgrade alternator and the big 3. Thanks again for your help and information!