Firggin drain

[Guest tony78_280z]

Previous Threads started by myself related to this problem...

http://forums.hybridz.org/showthread.php?t=98325&highlight=alternator

http://forums.hybridz.org/showthread.php?t=97202&highlight=alternator

http://forums.hybridz.org/showthread.php?t=97460&highlight=alternator

http://forums.hybridz.org/showthread.php?t=97201&highlight=alternator

 

To sum all that up...

 

At an idle and low speed operation my volt meter drops to about 10. When I rev up the motor several thousand rpms it'll jump up to about 16 and stay there for some time. It will slowly drop back down, particularly if the car comes to an idle for any length of time (such as at a stop light). Preiously it would drop so far that when I got to my destination, my battery would be to low to start the car again . I turned up my idle a bit, and removed the sensor wire and that seems to help, a little. (It does pull pretty hard in drive at that idle)

 

Battery: Tested good but low on water. I added some distilled water

Alternator: Tested good (GMC CS style alternator)

Vehicle: 78-280z with a Carbed GMC 305

 

My question...

 

Is there any way to get the damn alternator to spin faster at lower RPMs? Are there smaller pulley sizes? I have the one thick serpantine belt that runs the waterpump and the alternator. It is my only belt, and no it is not slipping. Any new ideas?

 

I carry jumper cables and a battery charger with me wherever I go, and disconect the battery once I get there. This is all getting kind of old.

[PeterZ]

16 volts is high enough to cause the water loss in your battery. Where are you taking measurements? If your battery sees 16 v during off-idle conditions and 10 volts at idle you have problems. Your battery may be sulfated and not taking/holding a proper charge, regulator problems, etc.. I recommend load testing the battery (250A for 15 seconds, should not drop below 9.8 v) and having an output test on the chg. system.

[Guest tony78_280z]

I took the battery to walmart (the place of purchase) and they put it on their 45 minute tester/charger. (standard procedure before replacement) They told me it was good.

 

The regulator is internal on the alternator, and the unit was tested at it's place of purchase. They declaired it good too.

 

I put water in it myself as it was sloshing pretty bad and the cells looked low. But this problem persisted both before and after the water, and the walmart test.

[PeterZ]

16v is still too high unless your meter is not accurate. Did you try a different battery? With such a voltage change you would have illumination problems as well as starting problems. To where does the charge wire go from the alternator? I have a similar problem on my Z8 in that I lose almost 2 volts from the alternator wire through the stock ammeter to the battery. Cleaning up the wiring helped my battery problem but I measure 14.5 volts at the alternator and only 12.75 at the battery. You may have a poor connection and are reading high volts at your meter connection but getting much less at the battery. Losing water is an indication of excessive charging. (15.5v or higher above 1500 RPM)

 

PS I'm curious as to what the charge voltage was during the Wall Mart test. sulfated batteries often charge up (and test well) but they require higher voltages than your system is capable of. Your battery goes dead a week or two later because the system can't charge at the higher voltage requirement.

[Guest 305240]

Hey Tony, Sounds like you have wired it just about any way it can be wired. I've used the 1 wire GM alt for years on almost everything I've owned. Fords, Dodges, Z cars, Jeeps. I run one wire to the Batt. any hot wire to my volt gauge. If I run an amp gauge, I run the wire from the alt thru the amp gauge first. I'm glad for volt gauges. Luckly I've never had a under hood or dash fire while running the amp gauge. I've never run any more wires to the alt. Never had to. They lasted for many years.

 

As for the overcharging, I have two hunches here. #1, Bad batt to body ground and/or bad engine to body ground. Bad grounds will burn an alt up as well as the batt. #2, Have your batt load tested as well as your alt at the old local mom and pop alt/starter rebuilder in your town. You know the place...it's been there forever. Their reputation is what keeps them in business. I bet you will get a different answer than the big parts houses tell you.

 

Oh, just thought of something. I've always used an aftermarket gauge. I also used an GM alt with the 1 wire 80 amp conversion from JcWhitney...20 bucks.

 

Honestly, I've never encountered any problem using that set up.

[Ed260Z]

To sum all that up...

 

At an idle and low speed operation my volt meter drops to about 10. When I rev up the motor several thousand rpms it'll jump up to about 16 and stay there for some time. It will slowly drop back down' date=' particularly if the car comes to an idle for any length of time (such as at a stop light). [/quote']

 

I've read your posts, and I still don't know what alt your useing. I'm assuming that you've done a ZX swap, or similar. My sugestion is that that regulator is not getting a good voltage read. (Check out my post on my 260Z alt swap) Also these alts don't make much juice below 900 rpm.

 

Good luck

[Guest tony78_280z]

I've read your posts' date=' and I still don't know what alt your useing. I'm assuming that you've done a ZX swap, or similar. My sugestion is that that regulator is not getting a good voltage read. (Check out my post on my 260Z alt swap) Also these alts don't make much juice below 900 rpm.

 

Good luck[/quote']

 

 

Battery: Tested good but low on water. I added some distilled water

Alternator: Tested good (GMC CS style alternator)

Vehicle: 78-280z with a Carbed GMC 305

Alternator CS Style And

Carbed GM 305 in a Z not a ZX

[Guest tony78_280z]

Start car

Everything is dim, blinkers stop, wipers slow, headlights are a no show

Rev motor

Everthing Brightens, Blinkers blink, wipers speed up, headlights pop up.

Idle drops and everything dims...

 

Ok, new news...

When I connect the battery's + post I notice a distict fizzle and spark suchas one gets when rubbing a live wire to ground. Is this normal, or is this a dirction I should persue in looking for a drain? I know things suchas a clock and a stereo constantly have a minute connection to the battery. Enough to drain it over several days, but will these small drains cause a fizzle spark situation? If I had a constant draw, would it cause the lights to dim at an idle?

[PeterZ]

Normal? no. Dim the lights at idle? possibly. If a common test light (remember those) in series between the disconnected battery cable and the related battery post lights the test light you have a problem. You won't know how big. Most test light bulbs will glow dimly with 0.1 amp current and are bright by 1 amp. 1/10 amp is enough to drain your aberage sized battery in a few days. If you have a spark at the post you may several amps. Use a good ammeter in series with the disconnected cable. Start with a high amperage meter (10A scale) first or you might blow the internal meter fuse. Go to smaller scale on meter to get a good reading. The amount of drain can help you figure where to look. (I.E. A reading of 3 amps could be an internal problem with the alternator) Disconnect fuses and observe the meter. If all the fuses are gone and you still have a drain the fun begins. You have to look for what is powered and not fused. Starter, ammeter, etc. (book time) good luck.

 

PS you may have 2 problems. A drain and something wrong with your charging system/wiring. What are the voltages at the alt. pos. post and at the battery during idle and 1500 RPM? The change in brightness is obviously not right.

 

P.S.P.S. NEO997X bring up a good point. Check the belt tension. Rev the engine until the voltage jumps up had keep it there for a few seconds. A slipping belt may not make noise but a slipping pulley will eaasily burn your hand. Use a wet rag to test for heat on the pulleys.