Charging system help needed

[DR1665]

Quoting toybreaker:

Quoting factory service manual:


System Operating Voltage, Manual Transmission Regulated Voltage

14.2-15.4 V at -4 deg F
13.9-14.9 V at 68 deg F
13.4-14.6 V at 140 deg F
13.1-14.5 V at 176 deg F






Just curious, as I've been dealing with this sort of gremlin for a little while, now. Problem happens exclusively once the engine has got up to operating temperature, particularly when it hasn't cooled off completely before restarting for another trip.

Ten to fifteen minutes into my evening commute, with the radio on at a decent level, no lights, fan on next-to-lowest speed, I'll let off the gas at about 60mph in 5th and feel the car stumble in gear. Clutch-in, tach drops to about 600rpm, bounces and stabilizes at 1200-ish. From there on, given a little slow-n-go rush hour madness, I start to get bucking in-gear in pretty much any gear.

Engaging the clutch results in idle jumping, almost instantaneously, up and down between 200-1000rpm before stalling completely. Still moving, I fire it back up, blip the throttle, and push through resistance to keep moving. Clutch in, same sh*t, stalls. This happened to me 3X just tonight on the way home (in left lane, rolling gridlock, had to keep it moving or get run down).

I killed the radio and fan, rolled the windows down, and drove it like a Prius. This is not how I wanted to learn heel-toe! Funny thing is, after about ten minutes with the accessories off, it seemed to smooth out. By the time I got home, I was able to do a WOT pull in 2nd and 3rd down a side street - just as crisp as ever.

As I'm familiar with the temperature variations (car runs like a top when cold), I immediately popped the hood and took the meter to the battery (still wearing a tie - proper gearhead, yeah?).

Optima "Red Top" (came with car 2 years ago).
off: 12.24VDC
idle: 13.71
~1500rpm, no load: 13.64VDC (dropped slowly)
~2000rpm, high beams, fogs, fan on high (AC not engaged), radio turned up: 13.50VDC

Seems a bit low to me. I switched it over to AC/DC Amps and pretty much saw 5A, with a few jumps to 6A-10.5A.

I'm borrowing a logger from boostedinaz Saturday morning, but will be driving the car to Long Beach on Thanksgiving. Really starting to suspect the alterator. Changed out CLT a couple weeks back (figured might as well while inspecting the harness there), new fuel filter a while before that.

For the record, when the engine starts trippin' balls like this, boost gauge remains steady around 20in vac and temp gauge (confirmed functional) doesn't budge. Just seems like it's not getting spark. :shrug

I'll probably see about swapping in the alternator off 195/2000, as that engine is sitting on a stand in the garage, but when I go to rebuild this one (if I don't go Saturn alternator on the rally car), are the replacement brushes sold at the dealership?

Thanks. Short of logging this sh*t, I figured I'd share my symptoms. I'll also bump this with results once I get them.

 

[toybreaker]

Maybe that's 464's way of saying you should try listening to actual music instead of that disgruntled ruckus that your speakers are grudgingly reproducing?






















/ubbthreads/images/graemlins/fawkd.gif














All kidding aside, That optima might be adding another variable to the equation, Brian.

12.24 for a resting voltage sounds a little low.

One thing about a spiral wound battery is they are greddy mo'fo's on the charging cycle, especially if they have been sitting for awhile and never charged back up to their full potential.

The alternator is not a battery charger, they are designed to power the vehicle and it's hotel loads (fuel pump/ignition/lights/heater/climate control and the like) while the engine is running.

Charging a discharged battery will put them under a load they won't like, especially if it's an agm or spiral cell design battery. The low internal resistance of that style battery can easily pull 60 amps (or more!) at the beginning of the charge cycle, and that'll put a hurtin on the internal regulator and brush/slip ring components and leave the alty playing catch up.

Might not be bad idea to put that red top on a charger and run it back up to full potential while you're near your wrenches/cold refridgerated beverages.

I'd also check the voltage drop in your cars wiring from the alty over to the battery.

Under a full hotel load, you should "see" just about the same voltage at the back of the alty that you "see" over at the battery. Any appreciable drop may mean you've got some troubles in the wiring/harness between the two. I've seen gravel/bits of grit get into the split loom section of the harness and damage the wiring where it runs accross the front of the car under the radiator.

This would also be an excellent time to look at the ground side of the equation. Make sure your engine is well grounded, and that the chassis ground is up to snuff.

You can check for a voltage drop on the ground side by putting the red lead of your voltmeter on the negative terminal of the battery and then put the black lead on the case of the alty under a full hotel load. Anything more than a couple of tenths of a volt spells trouble on the ground side of things. Do the same over to the firewall grounding points.

I usually add a better firewall ground on my cars. Just make a nice 4awg jumper that runs from the negative termonal over to the firewall. Clean the firewall down to bare, shiny metal, and toss a star washer under the lug and under the bolt head to get maximum continuity. Slather it with a little di-electric grease to cut down on the oxidization/corrosion, and you're good to go.

A few extra grounds from the engine to the chassis never hurt anything either. /ubbthreads/images/graemlins/smile.gif

We got's a few good folks out there in SoCal, (including one of the best people I've met on the net just south of the L.A. basin /ubbthreads/images/graemlins/worthy.gif ) so If you have any troubles give me a shout and I'll get you hooked up with the locals.


... just for the love of God, don't be bangin that disgruntled wanksters in a plumbers truck type ruckus when you pull into their driveway ...


capische /ubbthreads/images/graemlins/wink.gif







/ubbthreads/images/graemlins/cliffs.gif

Get a logger of your own, ya cheep bastid!

Check the wiring to and from the alty.

Carry a spare alty on long voyages.

If you run into problems in the desert at night, you can unplug one headlight to lessen the load and gain a couple hundred miles of range on a wounded charging system.




And lastly, improve your musical vocabulary.



Try some Zepplin, some Skinniard, some Van Halen (not Van Hagar) /ubbthreads/images/graemlins/tongue.gif

 

[DR1665]

"Disgruntled ruckus! /ubbthreads/images/graemlins/uhh.gif
For the record, John, when my radio is on, 90%+ of the time, it's on either NPR (news) or the local classical station, though I do enjoy pretty much anything which isn't country or rap produced after 1999. I'll jump from Shostakovitch to Rush to Pendulum to Dimmu Borgir to Slavic Soul Party on a whim, but 90% of the time, I'm listening to the news.

This is my first Optima. I would never buy one myself. Not worth the money, imo. Autozone's Duralast Golds have always served me well and you can't beat free replacement every couple of years, after the Arizona heat fries them. Thing is, this battery has been in the car since the day I took delivery and it's never needed so much as a jump. The alternator doesn't recharge the battery, but it makes sense it would maintain the charge over time. Could be the battery is just getting old, but I would have liked to have seen more voltage at the terminals the other night.

I'll be crawling under the car and checking things at the alty tomorrow, doing some drop testing as well. Didn't do it the other night, as I was still in slacks and a tie. Also, now that I think about it, I'm pretty sure I've got a box of 10AWG wire around the garage somewhere. Perfect for fresh/additional ground.

Finally, I'm holding out on the logger, as I'm going DSMap on both cars, in which case, I'm pretty sure I can log with my laptop. I got tired of having a PDA that was always dead when I needed it. Either buy batteries or put it on the charger, then re-install the software. Pffft.

Thanks John. I'll update with news as I get it.

 

[DR1665]

Just updating the results of my issues. Jury is still out, but I'm cautiously optimistic.

When I first took the DVOM to the battery terminals after work the other day, I was still dressed for work and didn't go beyond checking VDC at the battery terminals under various loads/speeds.

Yesterday, I decided to do a little charging system inspection/maintenance. Went to take the negative terminal loose - it was already loose! Turned out the same thing for the positive side. The posts looked dull and dirty.

So I replaced both terminals (the "marine type" terminal from Autozone is a near direct replacement for the positive terminal) and replaced the puny, factory ground from intake manifold to firewall with a 10AWG piece. All contacts were sanded to fresh metal and got a little dialectric grease.

Picked up 2.1VDC at the posts at idle. 14.44, baby. Symptoms have not returned, noticed the car doesn't sound supercharged anymore, either. Presumptive success.

First order of business = battery maintenance