MYROC19

Maybe somebody has an idea. I put in a high output alternator in my car, It was the Iceburg 140 amp kit through Summit. A whole new positive Batt. cable set up, and a brand new battery. My Car charges fine for the first couple of mins. Than is starts slowly dropping. I notice when the first fan kicks on, There is a big, quick, drop in volts, than it slowly comes back to near normal. On summer nights, with the A/C, lights and fans going, the volts are right on the red line of the gauge, if you put the wipers on, they move so damn slow!! I have no prob on the highway, I guess because im driving at higher RPM's to get the alt. spinning to keep up with the load. Why would I still have low voltage problems, with a new high perf. alt. new batt. and a whole new pos. wire loom?? And why such a huge loss of volts when the fans kick on, maybe I need a new relay?? Any help will be appreciated!!

Danno

First of all, it's normal to see a large voltage drop when the fans first come on. That's why I never recommend to hardwire the fans on all the time as you see here a lot. Second, with a larger output alt the idle volts will be lower at low rpm unless you run an undersized pulley. Did you install the 140 amp kit youself? The stator wires must be crimped tight to the rectifier pack as well as soldered. I have fixed a few where the solder melted and part of the stator or a phase of it was missing resulting in low output. If you are down in the red zone, that is not normal. With all accessories on at idle they will run on the low side, but not usually as low as you say. Another thing to check is when it's idleing tap the voltmeter and see if you get a bounce in voltage. If so, remove the trim, the metal bezel and plastic cover and gently pull the voltmeter out. It will have 2 small hex screws securing it and then it will pull out. Look on the back of the guage when it's out, you will see a small square ceramic block across the guage, remove the nuts retaining it and clean the contact surface of the block with alcohol or some decent electrical contact cleaner the remount it to the guage. Don't overtighten it, you can crack it. That block is a resistor and in some applications it is wired in series with the alt sense line. If it gets dirty it can result in low alt output. Also, there is a fuse link between the wire on the back of the alt to the battery, maybe you are running on the battery. On a cold start with the accessories off the guage on a normal TG should be up around the high side about the 10 or 11 o'clock position. Connections are always suspect also, case was my daughters Cavalier. The alt was humming like it was running full bore. No other problem was evident, batt was new, no starting problem. Cleaned the positive battery wire and problem solved. Check the starter junction and all grounds. Last, unplug the connector at the top of the alt and with the key on engine off measure each line on the plug on the wire end. One should read the same as the battery, the other should read a half a volt or so lower. The lower one is the sense line. If it is low or non-existent check at the fuse panel for a fuse labeled "fan/chg", if that fuse is blown you will get very low output. PM me if you need more help.

Freeze

Maybe it's just your Battery Gauge. Check the voltage with a Multimeter.

onebinky

iTrader: (1)

could be a bad ground also. Check to make sure you have a good connection between the alternator and the bracket, bracket and head, and the back of the head to the firewall. Like freeze said, you need to verify with a meter. The stock gauges aren't very accurate.

MYROC19

OK people, Sorry this is a bit long, I took the car out today for about a 15 min ride. My car hasnt been driven in a while, in the past yr and half, Im lucky I put 800 mi. on it. When I did my motor swap like 7 yrs ago, I made sure that I cleaned any paint off the alt. mounting brackets. where they made contact to the block, and I also did the same for the grounding strap from the head to the firewall. Tonight there was dew all over, so I had the headlights, eventually the 2 fans, rear def., and misc. stuff on. With no driving lights,( forgot to put on), my stock gauge was a tad above the redline, The blinkes were lucky they blinke once every 3 seconds!! I also forgot to mention, that I have full autometer gauges mounted in my car also. The Autometer volt gauge also read low to. As far as I can remeber, I had this car almost 11 yrs now, I cant remeber this car ever charging decent at night with everything going. Another ques. I have, If It was a bad night, weather wise, And I had all my lights on, rear def. front def. or heater motor going, and wipers on, Do I have to worry about my car dieing at a light?? My buddy works at an alternator place, hes the one that built the Iceburg kit for me, He was amazed when he bench tested the alt. on how much power it put out, should I have him put on (help me out here) either a smaller or bigger pully to try and keep the alt. spinning a little faster at idle?? Maybe that might bring the volts up a little when Im sitting at idle. Thanks again eveybody!!

junkyarddog

You have a problem within the wiring!!!

an underdrive pulley won't solve any of the problems you are having, although it is a good idea.....once you fix the problem.

do the wipers and blinkers work correctly with the key turned to ACC or ON?

there is no good way to check the wiring without a multimeter, forget the gauge on the dash. infact, cover it with a piece of duct tape for now. you can find a good multimeter for under $30, I even have one I purchased for $2.99, perfectly acceptable for automotive work.

lykan

Have you checked the condition and size of your battery. A lot of smaller batteries just don't have the reserve to supply all of those acessories.

I have had similar problems and a larger replacment battery has solved the problem.

Run the car with no accesories on, let it run for a while to charge the battery to full. The pull the cables and checkt he voltage at the battery.

When I go to replace my battery I never ask what's stock and have them give me the replacment. I look for the largest battery with the most CCA(cold cranking amp) and squeeze that one in. I usually have no alternator/voltage problems after a bigger battery has been put in.

**edit** It's obivious the charging system should be in great conditon with the kit your friend put in. It has to be either some terrible wires to your fuse box/accessories, or a bad/weak battery.

Petes 84Z28

You may need to upgrade the charging line from the alternator to the battery so it can better transfer the available current.

Pete

Danno

They never will charge at idle at night with as many accessories on as you say. I too have installed a few of the "iceberg" kits to upgrade the CS alt from 105 to 140 amps, however remember that even the CS 144 stock GM unit was only rated at 120 amps in the vehicle under normal load with normal driving conditions. I run a CS 144 and have run the upgraded "iceberg" unit also and they are roughly the same under idle conditions. As was stated before and I have posted this too many times the condition of the battery is THE most critical part of any auto electrical system. And contrary to any post you read, an alt will never fully charge a battery. The best you can expect is to maintain the battery at 75-80% of rated capacity. My 89 sits a lot in the summer, I commute on a motorcycle. The battery "eye" was no longer green indicating a low state of charge. I drove it for over a week with nothing on but the radio and it never charged. A long overnight trickle brought it right up and it has stayed there. I recommend to everyone that they do a trickle once a month, a simple charger that plugs into the cigarette lighter does fine. Give it a 12-16 hour charge and you will be surprised a how much better the entire system operates. Someone mentioned a larger capacity battery, makes no difference in the scheme of things. It only gives you more time before you reach the point where the battery becomes technically discharged. Generally this is not an issue since when you come off idle the alt will begin to put out more replacing capacity lost when you are making battery demand high. Stock for a TG is a Delco 75A12, it means simply that you can draw 75 amps for 1 hr assuming it's fully charged before you get to the point where it is no longer considered to be useful. Sorry for being so long, but the auto charging system is very misunderstood by many people.

MYROC19

In reply to JUNKYARDDOG in my first post, I put in a whole new POS. wire loom, which had a new ALT. lead, fused link, and lead to the starter, its seemed to help a little with the problem when it was first installed, but not too much. As far as the blinkers, they seem to operate close to normal with just the ACC. on and no motor running. In response to LYKAN as in my first post, it is a brand new AC DELCO 720 CCA (I think) batt. About a month old. In response to PETES84Z28 The line that came with the replacement POS cable unit that goes to the ALT actully looked a little thicker than the stock. Like DANNO said abot the charging at night, Ive owned MY ROC for like 11 yrs now, and I cant remeber it ever charging good at night, I just cant remeber it actually going as low as it does, There has been nights where I needed the lights, rear def, wipers, heater fan all on, and the volts were so low at a light, that I thought the car would stall on me, I actually pre-loaded the gas to raise the RPM's a little. its just funny that with a few extra RPM's, the volts go up to normal again, thats why I asked about a different pully on the alt. As soon as I hit the gas to go at a green light, the volts go up to normal!! Thanks for the help people, keep it comming!!!!

junkyarddog

I do apologze.. at first glance, it seemed like a simple charging problem.

Ask your alternator friend to back me up here, I do rember a JBL rep mentioning that, "high current alternators require an underdrive pulley to put out 12.6 volts at idle," during an autosound seminar. It has something to do with the thicker coil wires and more diodes in the rectifier bridge.

underdrive is a smaller diameter and requires a new belt, it should be easy to find if you have a serpintine.

since you car works fine at cruise speeds and youv'e already done all of that wiring.....unless there is still some overlooked serious problem with the wiring, it seems that you've already found the problem.

If it were my car, I would be checking voltage drops through every critical connection, just to be sure.


consider exchanging the battery if it has been deep cycled (10 volts or less).

Danno

Without getting boring, let me explain what actually is happening. Any brand of modern alt uses a solid state regulator IC, in the GM Si and CS they use a thick film hybrid IC located internally. The IC looks at a window of voltage as demand is placed on the charging system based on load. When demand is high as is the case with everything on you run from the battery and the voltage sensed by the alt tells it what to do. If the alt where to try to keep up with very high demand it would overheat the diode or rectifier block possibly causing failure. When voltage sensed is low beyond a certain point it will INTENTIONALLY back down to protect itself. Some regualtor IC's also have a thermal sense, rectifier pack gets too hot it backs down output. In the case of an iceberg the size of the stator windings are increased, however nothing in the field is changed so things at idle stay the same or get worse. The difference between the kit and a true CS-144 unit is the CS-144 has a slightly larger rotor if I not mistaken, hence it has more output at idle but not by very much. With all accessories on the voltage still takes a pretty big dip. Installing an underdrive pully will help with your problem but many manufacturers warn of premature alt failure if one is used. Thats up to you, but depending on how much it bothers you a 144 may be the way to go. I got one from a boneyard after much hunting, took it apart and put in new brushes and it works well. I mentioned there was not much difference but it did actually come up a little based on the iceberg converted CS-130. GM states in a sevice manual for a Corvette with a 144 that it will put out approx 124 amps at full output. The stock CS-130 puts out about a max of 83 amps when it's a 105 amp rated unit. These figures are ideal numbers, generally it's best case with a perfect battery. Truthfully unless it really affects operation of the vehicle it may be best to leave it alone.

junkyarddog

having worked at a sound shop, I've seen some outrageous stuff.

One of the managers had a '98 cavalier running riduculous system with thousands of JL Audio watts, a strobe driver from a stage set or night club for all the lights....he did has own alternator windings. One time, I noticed, as well as 12 alarm horns, there was also an external DC voltage regulator mounted near the radiator. I'm sure it wasn't made for a car, but it could certainly handle the job. The alternator was all wire, and the huge unit (about the size of a small battery) did all of the hard work of keeping a steady voltage.

It takes a sick in the head induvidual to do all of that with a car, but that is thinking 'outside the box'!

the regulator was most likley part of an in store DC power supply for the displays. probably too expensive, unless you can obtain strait from the source....or build one yourslef.

MYROC19

I did forget to mention, that the Iceburg kit that I put in, was the 140 Amp kit with the heavy duty bearing kit too. When I get a chance, I'm gonna try my luck with the smaller Alt pully. If I can get the Alt. to spin just a few extra RPM's at Idle, I think it will get me out of that "Worry zone" I have too heard of underdrive pullys giving pre-mature bearing wear, but since the kit came with the bigger heavy duty bearing, I'll take my chance. My car has the old multi belt set up, so It really wont be that much of a pain. I'll keep you guys posted on what happens. Thanks for all your opinions, they helped alot!!

joshwilson3

.

MYROC19

In response to JoshWilson3 , My car always seemed to have this problem since i bought it. I bought the car off the original owner with 20,000 miles on it like 11 yrs ago. If you read my other threads, over the years, I put 2 motors in, I did my best to check all the wires, replaced the whole Pos. cable set up, cleaned all ground contacts, etc. I had this problem before I upgraded the Alt., thats half the reason I put it in my car, to see if it would help. I have the stock gauges, and after market Autometers, and the both read the same. Like I said, the only complaints I have, is at idle. You seem to be a lucky one!! My car idles at normal RPM's in drive, if I pre-load it maybe 200 Rpm's more, it seems to bring the volts to more of a safe reading, Thats why Im gonna try the pully. I'll keep ya's posted when I do the switch!! Just wondering... After all these posts, Has anyody else had, or know anybody thats had any problems like mine??

3rdGenBlackBird

I have the same problem, and I'm still trying to fix it. I have to put the car into neutral as often as possible to let the rpm's even out the voltage drain. In heavy traffic (especially at night/in the rain) I have to keep the rpm's up to keep my lights from dimming. And of course, as long as I'm giving it gas (freeway, accelerating, etc.) everything operates normally and the volt gauge shows 13 or (usually) higher.

My firebird had this problem when I bought it, and I thought I had this problem tackled earlier this year, but it recently returned with a vengeance. I trickle charge my battery every night or every other night just in case I get caught in traffic or in the rain. (There was traffic from hell PLUS pouring rain on the way home from work tonight- sucked to be me!)

This seems to be an intermittent problem (going from negligible to bad to HORRIBLE) for me from week to week. When you find your answer please let us know!!

Danno

Same story as me. Bought my 89 in late 90 with 19k, always did it. Fact is depending on condition of battery, alt, it's in fact normal. Add up all the stuff current wise and the alt cannot and will not keep up with demand at idle. During periods at idle in drive with mine it stays on the low side. Kick it into neutral and it pops up. There is really nothing you will do about it. The only thing that will help a little as I said is a true CS-144 unit, not a converted one. Up to you as to whether it's worth the expense for a few extra amps at idle.