New alternator throw a code?

[jarred15801]

I have a 97Q and I fried my stock alternator. Amp for stereo system draws to much power, so instead of replacing with stock 110amp alt and most likely frying it again I bought a high output 220amp alt. The alt is supposed to be wired with a 4 gauge wire and 250 amp fuse directly to the positive battery terminal, the alt is self regulating so no worries about overcharging battery. This is where I'm a little worried though, there's nothing for the original alternator plugs from the harness to go into, your supposed to just cover so they don't short or anything which isn't a problem. But won't my check engine light come on because they are unplugged? Or wouldn't it? Because it definitely didn't come on when my stock alternator was dying.

[Q45tech]

High output alternators may not supply sufficient operating voltage at low rpms [idle].You need to study the rpms vs current/voltage chart vs oem.

OEM balance max capacity at high rpms vs idling capacity.

Pretty tough to comply when you exceed 140 amperes max.

Use pulley diameter vs crank pulley diameter ratio to arrive at actual alternator rpm vs engine rpm. Usually.............. /2.5.

[jarred15801]

110amps at idle and 220amps at 1200rpms

[Q45tech]

High output alternators may not supply sufficient operating voltage at low rpms [idle].You need to study the rpms vs current/voltage chart vs oem.

OEM balance max capacity at high rpms vs idling capacity.

Pretty tough to comply when you exceed 140 amperes max.

Use pulley diameter vs crank pulley diameter ratio to arrive at actual alternator rpm vs engine rpm. Usually.............. /2.5.

http://www.pkys.com/alternator_installation.htm

In the middle of this web page you will see a graph that show the higher the peak ampere capacity the higher the MINIMUM rpm necessary to get the alternator to start working.............look at curve slopes!!!!!!!!!!!!!!!!

You may have to increase engine IDLE RPM to get enough current for the system to function correctly.

[jarred15801]

I know what your saying and this is what the company told me idle it will put out 110amps...at 1200rpms it will put out 220amps. 1200rpms is pretty low to be making 220amps, idle on my car is around 800 i believe? I'm almost never below 2000rpms though while in my car because I'm always driving. Never really just sitting there at idle. So the rpms and amperage will not be any problem.

I'm just worried about a check engine light because im bypassing the original alternator plug ins and running a 4 gauge wire with fuse to my battery. Will that throw a code or doesn't the alternator throw codes? because when my alternator was nearly dead there was still no code at all.
Modified by jarred15801 at 12:45 PM 6/30/2009

[Q45tech]

From web site:http://www.nationsautoelectric....html

"The second question you'll want to ask the manufacturer or reseller is: What idle speed are you basing your idle output amperage on? What we are looking for here is the number revolutions per minute (RPM) of the alternator pulley when the vehicle is idling. For many years, the industry standard was 2400 RPM, and there was a time when this was accurate. However, with today's modern vehicles, idle speeds are typically between 1600 and 1900 RPM. Despite this fact, you will find that some companies are still using the inflated idle speed of the past when calculating their amperage output ratings in an effort to advertise the alternator as a "high output" unit. This is not only unfair to the consumer; it also creates a very dangerous situation for the vehicles electrical system.

Lastly, the third question to ask is: How did you determine the pulley speed at engine idle? The importance of this question is largely based on the answer you receive to the first two questions. We are not able to speak for other manufacturers, and how they get their numbers, but at Nations, we use the following formula: test, measure, analyze, then test, measure and analyze again, and then confirm the results by testing, measuring, and analyzing yet again. We perform extensive on-car load testing to our alternators to make absolutely certain that our alternators will deliver what we claim and have conducted extensive bench testing to every single one of the alternators that we offer, and we don't stop until we get it right! When installed properly, more amperage will not hurt your vehicles electrical system, but not having enough certainly can!

Another site: It is possible to modify this ratio by changing either the alternator pulley size or the crank pulley size. The alternator’s pulley being the least expensive of the two. This is also why if you have done this already via “Power Pulleys”, you are likely having charging problems at low rpm with a stock alternator.

Typically you want the lowest possible ratio possible. This is because an alternator requires approximately 1hp for every 22.5amps of output, times the pulley ratio. So the lower the pulley ratio, the less the hp the alternator needs to take from your engine.

One thing you should never do though is sacrifice system voltage for a lower pulley ratio. As you can see quickly doing some playing around with your system requirements, there is not a whole lot of hp to gain by lowering your pulley ratio. Example: a 100amp load on an alternator with a 3 to 1 ratio has a load of 13.3hp on the motor. Reducing the pulley ratio to 2 to 1, only will save 4.4hp. Which is a chunk of hp. However if doing so decreases your system voltage from 14.9 to 12.9 volts, you will likely lose a noticeable percentage of overall engine hp. This is simply because your electronic ignition requires voltage and amperage to run, if it doesn’t see what it needs, then its performance is effected. See the article on “System Voltage” for a full explanation. The short story is, simply put, having enough amperage at idle is more important than saving a couple of HP by reducing the pulley ratio.

Alternators have fixed charged curves. The only way to adjust this curves is to replace the alternator with a different one. Your engine idle is a fairly fixed part of the equation as well. It can be adjusted slightly up or down, but no drastic changes are possible. By far the easiest thing to adjust is the pulley ratio. If you need to move higher up into an alternators charge curve to meet your system requirements, you simply put a smaller pulley on the alternator.

This however has some limitations. The first is it may not be possible to but a small enough pulley on the alternator to get enough at idle amperage. In this case you need to get a higher at idle output alternator. You also have to bare in mind the maximum speed the alternator can turn. Typically big body (big truck, EMS) alternators will not survive over 8000rpm constant rpm. Automotive units are around 16,000rpm, but double roller units can survive momentary bursts higher than that. However even double roller bearing units that see over 20000 rpm should have there bearings checked frequently, and have only top quality bearings installed. We do not recommend any units with needle bearings to see in excess of 18,000rpm.

Now back to deciding on what pulley ratio to use. You can’t really until you decide on what alternator you are going to use. You only need to consider it when searching for a new unit. Most automotive type alternators start charging around 1500 rotor rpm. They start producing usable amperage just over 2000 rotor rpm, and are well into their output curve by 3000 rotor rpm.

Typical pulley ratios vary from 1.5 for high rpm motors, 2-2.5 for drag cars, 3 for street driven cars. This will put you in the ballpark, i.e. give you an idea when looking at alternators what one is likely going to work in your application. The pulley ratio then can be tailored to fit your setup. But if your engine idles at 750rpm, and your system at idle requirements is 100amps, there is no point in looking at alternators that produce less than 100amps at 2250 rotor rpm, for you cannot adjust the pulley ratio to meet the requirements. You can consider 3.35 to be likely the highest pulley ratio available, for most cars.

Big trucks and EMS applications have to bare in mind that the pulley ratio is not near as adjustable as in automotive applications. Further the maximum rpm is very crucial, and cannot be pushed. This is because the units have much larger rotors, that can easy fly apart because of momentum. The larger rotors make the alternator turn on at a lot lower rotor rpm, and the low end performance is greatly increased.

The last thing to consider about pulley ratio is belt wrap. The smaller the diameter of alternator pulley, the less contact the belt has with the pulley. In high output applications it is important to use as large as pulley as possible. Or insure 180 degrees of belt wrap. This will limit the amount of belt slippage.

While on the subject of pulleys, did you know that a serpentine pulley has a lot more contact surface than the older “V” belts. There are very few applications in the automotive industry where alternators with over 95amps of output only had a single groove “V” belt. So if you have not got one already, we suggest purchasing a 6groove serpentine belt system for any high out put alternator application. If you are going over 200amps, an 8 groove system is a must.

[jarred15801]

but either may its being measured it should be sufficient considering 110amps at idle and 220amps at 1200 rpms which would have to me engine rpm's correct? because if it were referring to the alt at 1200rpms then at a 2.5-3 ratio that means the car engine would only be idling at 400-480rpms which isnt possible. and engine at 1200rpms full amperage from alternator won't be bad at all becasue thats basically putting the car in drive.

[qship96]

ok, got about 1/2 way through that and decided it was less painful to abandon the idea of "upgrading" the alternator when the current one dies than to continue reading that post and then playing "detective" to source a high output alternator that was truly producing more juice than the OEM part from idle speed to redline!!!!

[lino]

Do you have a Power Capacitor?

I replaced the 60 amp stock alternator in my Mercedes 300CE with a 150 amp unit from an AMG CL55 and it worked great for me. The only thing I did was use the old pulley and used 0 gauge power wire.

[jarred15801]

No capacitors are junk, they can only supply power for a brief second, not enough to help anything. mostly just for looks.

[TellarHK]

Capacitors are extremely useful in specific circumstances, such as high-output audio systems where you're only using the capacitors as an additional source of juice to make sure your amplifiers have enough power for those brief moments when the bass volume gets really ramped up.

If you're using too much juice for a capacitor to do the trick, you're building your system wrong.

[jarred15801]

No it's not built wrong, they are just junk. They are a waste of money and just for looks. They do almost nothing at all. I know many people that have used them say that, many audio stores that don't just want your money and tell you the truth will say that, and look around the web you'll read it many places that they are garbage. I'll post some links soon.

look around on here all you will read is negative feedback on them

http://caraudioforum.com/searc...61306
Modified by jarred15801 at 7:08 AM 7/1/2009

[Q45tech]

Obviously, a trunk mounted battery charged thru isolation diodes for the exclusive use of the amplifer is a better and less costly method than a proper capacitor in the size* to do any good on peaks.

The problem is a 1 Farad Capacitor while large in appearance is really small in function.

Something useful like a 25-50 Farad QUALITY unit will cost over $500

1 Farad is 1 volt for 1 ampere for 1 secondso 15 Farads would power an amplifier for 1 second with zero sound.

[jarred15801]

Thank you for helping explain my point. I fried my alternator that's why I'm getting a high output. Stock 110amp alternator using say 60-70 for normal car usage then say my fans kick on the radiator that's probably another 30-40 amps. Which leaves me maybe 20 amps at the very most left over to power stereo or store in battery. My system alone is trying to draw around 120 amps. Therefore replacing with another stock alternator and getting a capacitor or a 2nd battery just won't cut it. Because there's no amperage left over to even store in the batteries or cap for the system to pull from when the stock alt can't supply the demand. Another reason caps don't do anything.

[bullittandy]

Isn't a little late to be getting cold feet? You've built an enormous stereo system, cooked your stock alternator and have already bought an untested aftermarket alternator.

Just put it on and see what happens.

[maxnix]

And document how you will install the pulley for the 8 groove serpentine belt, please.

Sometimes big, heavy audio systems are best ledt to immovable locations like the home. Certainly the environmental variables and volume of the listening space and be attenuated better.

[jarred15801]

I'm not getting cold feet? I'm just asking do you guys know if you get a check engine light from an alternator? Wondering if ill get one when i put the high output alt in bc you leave the stock harness unplugged. That's the only reason i started this thread was to ask that question just like i did in my original post. I wasn't asking about output and rpms or talking about junk capacitors. I had one simple question so I'd like an answer for that question, not all this other stuff that i did not ask. And I'm going to put the high output one in just waiting on the fuse block and power wire to get here. Also what makes you say this is an "untested aftermarket alternator"?

[qship96]

Yes?

No?

Maybe?

Guess you will find out for yourself once you try?

[Q45tech]

My county has passed legislation that makes it illegal and a public nuisance to play music which can be heard or measured outside of the vehicle with windows up or down!The old 50 foot limit was just too liberal.$100-$500 fine for first offense...............no warning tickets allowed.

Hopefully all states and counties will do likewise to protect innocent ears!

[qship96]

What are all the wannabe ganstas in the city going to do???? No more cruzin in their shiny hoopties with the distorted stolen radios blastin through kraco speakers and a sub???

[jarred15801]

Yes?

No?

Maybe?

Guess you will find out for yourself once you try?

thanks it seems you have the most valuble input in every thread topic...once again if you don't know don't talk..your words are worthless and a waste of time

[goody90q45]

.........I'm just asking do you guys know if you get a check engine light from an alternator? Wondering if ill get one when i put the high output alt in bc you leave the stock harness unplugged........

The CEL is related to emissions and an unplugged alternator will not set it off or throw codes to the ECU. Look through the list of ECU code fixes and none of them says replace battery or alternator. What it will probably do is set off the 3 lights that warn of charging problems- Brake light, Air Bag light (IIRC) and LOW BATTERY CHARGE warning in the message center.

[jarred15801]

The CEL is related to emissions and an unplugged alternator will not set it off or throw codes to the ECU. Look through the list of ECU code fixes and none of them says replace battery or alternator. What it will probably do is set off the 3 lights that warn of charging problems- Brake light, Air Bag light (IIRC) and LOW BATTERY CHARGE warning in the message center.

thank you..exactly what i was looking for