Quality Power Alternator, Big 3, Voltage spikes

[RotaryDreamz]

96 4runner limited, aftermarket fogs, couple of lightbars, multiple usb charging ports for the family, and a winch.

Sorry for the long post, trying to be as detailed as possible.

I purchased a Quality Power high output Alternator and did the Big3 upgrade at the same time. Other than a slight whine from the alternator since install, I didnt start noticing an issue until one of my buddies asked me if I kept high beaming him while I was following him off trail. Everytime I gave it gas, my lights would brighten up. I put a volt meter at the battery, and once I gave it throttle, my voltage spiked up as high as 20 volts. Yikes! I contacted Quality Power, they told me to send it back. I'm assuming they're going to replace the voltage regulator and ship it back. While waiting for the replacement, I drove around with the OEM unit and had no voltage spikes or issues whatsoever. Awesome.

A week later I received the alternator back and slapped it in, I did some basic tests and it seemed like everything was all good. 2 months later is the 1st time I drove it at night since, and sure enough, my damn lights keep brightening up everytime I give it gas.

I hookup the VOM, do some tests and it jumps up to 14.5 -.8 everytime I give it gas with lights off. Once I turn on my headlights, give it gas it shoots up to 15.5 and the lights get bright. Wtf! It doesnt do this with my OEM unit.

So I assume, it's just a crappy Quality Power unit. I end up on LCEngineering's website and see they offer a similar alternator. Purchased it. 2 days later I receive a tracking number from UPS and it's being shipped from Quality Power! Just Great.

I decide to just give it a try since it's a new unit, but ends up doing the same thing.

So, I have a couple of questions for you gurus. Could I buy an external voltage regulator to work with my quality power alternator to stop these spikes like the one in the link below?

Or should I just keep my OEM one in and use it for now? I use my winch maybe once a year.

I had a pretty interesting read about this guys 99 Taco and Quality Power alternators, if anyone cares to take the time.

Quality Power alternator - Electrical-battery- Alternators- Wiring - #1 Car Audio Enthusiast Forum in the world! | SMD | Meade916

Any input is appreciated.

PS: for personal preference, I do not want to use a GM Cs144.


External voltage regulator:

Amazon.com: NEW 14-20V 14V - 20V Adjustable Voltage Regulator: Automotive

Thanks

- Sean

 

[Dieselchessy]

Having read all that it sounds like a voltage regulator wouldn’t work for you.
Sounds like your alternator isn’t charging at idle and then kicks in and spikes the voltage once you get up above idle.

A voltage regulator won’t help you at idle if the alternator isn’t outputting. That thread makes it sound like you need a better quality alternator.

 

[Skulking]

Maybe I missed in, but I don't see a measurement of idle voltage. Based on the thread you linked to I'm curious if your alternator is actually charging your battery at idle.

I'd be concerned about the high voltages you are seeing with RPM. It's probably just a matter of time before you damage something with that.

The voltage regulator you linked to will not work. I don't know enough about electronics to know if the idea behind it will work, but that voltage regulator is only rated for 15 amps which is way less than what you need if you are trying to regulate the alternator output.

 

[19963.4lsr5]

There seem to be something still up with its ability to regulate voltage since it was 14.8 and then 15.5 under load.

You already did the Big 3 which means your engine to frame to negative battery post should be good.

If you are using the stock framed alternator the only real way they are going to increase its output is by raising the desired voltage. And maybe add a few more wraps around the stator.


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[RotaryDreamz]

Thanks for the responses! You guys are awesome.

Got some pics below to show what I'm seeing.

Cold start, my cab volt meter shows 14.2, 14.3 on VOM. It's usually .1 off from my VOM.

Once warmed up in park, it stays at a 13.9-14.0.

As I'm driving, doesnt matter what rpm or speed, stays at a steady 13.8

Warmed up in Drive at a stoplight it stays at a 12.6


My idle RPM is always around 590-620. Now the weird thing I noticed, is that it seems my idle voltage drops under 640 rpm. At 640-660, my voltage will be 13.3-13.8. I tried to snap a quick picture of my voltage at 640 rpm before it settles around 600.

Either way, with the headlights on, in park idle voltage at 13.8 will still spike up to 15 once I give it throttle and my headlights will brighten. Headlights off, throttle, wont jump past 14.8. OEM Denso back in, no issues whatsoever.

Would you guys agree that it must be the "quality" of Quality Powers alternator or am I missing something?

Cold start:

Driving voltage:

Stoplight idle voltage:

Voltage @ 640 RPM:

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[snydmax]

Bad “quality” alternator... return it if you can


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[gamefreakgc]

Voltage meters from interior wiring are innacurate, first thing. I chased some poor voltage numbers and was seeing as low at 12.3V from the OBD port. Well turns out my battery is fine at idle, it's just voltage drop from the wiring. So when people are asking about taking voltage readings from the battery, they literally mean stick a volt meter on the positive and negative terminals of the battery. Nothing else is accurate and will have voltage drop. You can still get a cold reading, hot reading, idle reading and under load reading from the engine bay (alligator clips make this easier).

I know you said you don't want to use the CS144 alternators. I'm sure you have good reasons. When you start modifying a vehicle away from it's stock components, you're going to start to incur side-effects of changing out factory components designed for ease of use and dependability with components not designed for our vehicles. As one who drives a highly modified engine, I've fixed the side-effects that I can and learned to live with the rest. If you don't like how the increase alternators run and with larger voltage movement and a wider range of operation, then I recommend switching back to a stock DENSO alternator. Unless you're getting dead batteries or alternator whine it might be best to stick with what you have (USB chargers aren't going to drain the battery while driving). Another option is the CS144's as they are also stock alternators for many GM vehicles (still used in newer Corvettes!) designed to run reliably for a long time. They are not some souped-up modified component masquerading as a stock unit but factory designed unit.

Hope that helps with the decision making process.

 

[RotaryDreamz]

Bad “quality” alternator... return it if you can


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I feel the same. Already emailed a request to return for a refund.

Voltage meters from interior wiring are innacurate, first thing. I chased some poor voltage numbers and was seeing as low at 12.3V from the OBD port. Well turns out my battery is fine at idle, it's just voltage drop from the wiring. So when people are asking about taking voltage readings from the battery, they literally mean stick a volt meter on the positive and negative terminals of the battery. Nothing else is accurate and will have voltage drop. You can still get a cold reading, hot reading, idle reading and under load reading from the engine bay (alligator clips make this easier).

I know you said you don't want to use the CS144 alternators. I'm sure you have good reasons. When you start modifying a vehicle away from it's stock components, you're going to start to incur side-effects of changing out factory components designed for ease of use and dependability with components not designed for our vehicles. As one who drives a highly modified engine, I've fixed the side-effects that I can and learned to live with the rest. If you don't like how the increase alternators run and with larger voltage movement and a wider range of operation, then I recommend switching back to a stock DENSO alternator. Unless you're getting dead batteries or alternator whine it might be best to stick with what you have (USB chargers aren't going to drain the battery while driving). Another option is the CS144's as they are also stock alternators for many GM vehicles (still used in newer Corvettes!) designed to run reliably for a long time. They are not some souped-up modified component masquerading as a stock unit but factory designed unit.

Hope that helps with the decision making process.

I definitely agree that once you start modifying a vehicle the dependability goes down and it's just not the same as original. I've owned multiple Rx7's and went through 3 motors on my highly modified FD. You probably already know rotary engines just aren't that forgiving when issues arise. Haha. Definitely not like these 3rd gens. Boy was my wife happy once I sold my last wankel.

I guess I'm more worried about the high voltage spikes on my system than anything. Noone on the road has accused me of highbeaming them yet. I just feel it's not right. Is 15.5 too high of a spike on my system? To be fair, I'm witnessing the voltage spike with my VOM directly connected to the battery terminals. I just use my interior volt reader as an average reading on long trips.

I'll give the CS144 another read, and research the comparison. I really just wanted a HO alternator to be safe when I'm out winching. Really wasnt expecting to have a unique issue like this. Thanks for your time!

 

[snydmax]

I’d suggest you look into a dual battery setup ... that will give you more power storage for winching and accessories, etc. An HO alternator isn’t a bad idea but the one you got isn’t working properly, reminds me of what the one in my boat would do when it bit the dust... it would overcharge as the RPM went up, a simple rebuild fixed that


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[RotaryDreamz]

I’d suggest you look into a dual battery setup ... that will give you more power storage for winching and accessories, etc. An HO alternator isn’t a bad idea but the one you got isn’t working properly, reminds me of what the one in my boat would do when it bit the dust... it would overcharge as the RPM went up, a simple rebuild fixed that


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I was always curious about the dual battery setup. I didnt really feel the need for that much extra juice. I have a Honda generator I take with me on every camping and hunting trip. Going dual battery route, I wouldn't need to bring my generator and extra gas. It would save me some room in the back. Interesting!

 

[det107]

I'll give the CS144 another read, and research the comparison.

I used Doc2012's Big 3 tutorial using a CS144 alternator to install mine. Granted I still don't have a winch let alone a light bar but it still functions properly.

The next step for me is to upgrade the wiring & battery posts-

 

[RotaryDreamz]

I used Doc2012's Big 3 tutorial using a CS144 alternator to install mine. Granted I still don't have a winch let alone a light bar but it still functions properly.

The next step for me is to upgrade the wiring & battery posts-

Thanks, I'll take a look at that write up more thoroughly this time. I didnt give it a chance before.

The big 3 is definitely a must do mod I feel. Especially when changing out that wimpy ground to fender wire.