logizec

I have a 93 oldsmobile cutlass supreme 3.1L.

On Monday it died in the middle of the street, and wouldn't start. Had it towed and looked at. They checked the alternator (put under a 30 minute stress test), and it came back fine. Put in a new battery and it works like normal. However, I sat in a parking lot just listening to music for 45 minutes yesterday and i had to have the car jumped. I drove the car home from work last night at midnight, and parked it for the night. Went to go start it 14 hours later and it does not have enough volts to start the car (around 9).

The mechanic has no idea, and neither do i. The car runs fine (with a hesitation for the first 5 minutes) when you first start it. When I use the rear defrost, front defrost and lights the car drops voltage to 12 or below.

Lady72nRob71

What are the voltages across the battery (fully charged) when:
Car is off, key removed
Car running at adle speed, all accessories off
Car idling, lights and AC on

Time to put an ammeter inline with the battery to determine the amount of current flow when the key is off.

Does the clock in the radio go blank when the key is off?

BTW, welcome to the site!

logizec

When the car is off : 13v according to the meter on the dash.
Running with accessories off : 13v
Car idling, lights and ac on : 11v

I am getting a ammeter tomorrow to test everything else out. What exactly should i be testing? Also, should i touch it to the battery terminal, or just the cable itself?

All my electric still works like normal, even when the car doesn't start. If i turn it over and it fails several times, the battery will go completely dead. However, i can still use my windows, radio and electric locks (when the car doesn't start)

Thanks!

Lady72nRob71

If the wiring looks okay (like at the connections), it sounds like an alternator or regulator problem to me. The reg is probably inside the alt so I would take it to another shop for testing. It has been known to have shops not test them right.

logizec

The alternator was pulled out and stress tested. When I am driving the car, the voltage meter on the dash shows that it is charging, and reaches about 14v in total. The problem seems to be when the car is off, something is draining the battery.

Lady72nRob71

I know for sure that 11V with lights & AC on is bad. Should be 13.5-14V.
Put a voltmeter across the battery terminals to verify your dash gauge is working right.

To check the drain:
With key off and all accessories off, you will need to disconnect the battery ground cable and insert your ammeter inline with that loose cable and the negative battery post. Post your results here.
If more than a few microamps:
Unplug the alternator first, then start pulling fuses until the drain goes away. This will tell you what circuit to look on.
Many of the factory GM stereos back then developed a fault for keeping the clock display on at all times - make sure yours blanks out when key is off.

White_Knuckles

The D/C ammeter must be placed is series with the battery cable. You may use a basic Volt/Ohm meter set to amperage (MA) scale observing polarity where the positive lead (red) is on the disconnected positive batt. cable and the negative (black) meter lead is connected to the Batt. positive post. Be careful with the meter lead connection points on the meter. There is usually a special position (plug in spot) for the amperage test function.

You are reading current flow (in milliamps - amps) through the cable where the meter is in series between the cable and Batt. post. A normal current flow when the key is off would be in the milliamp range where 1000 milliamps is equal to 1 amp. 30 milliamps or less would be "normal" lets say from your stereo headunit using power to retain it's settings. This device draw is known as parasitic load. It would not kill your battery unless excessive. Opening the door turns on the dome light(s) now reading 500+ MA (1/2 Amp) draw. DO NOT test loads with the meter such as turning on the lights etc. the dome light example was just for understanding, not meant for actual testing. The meter will smoke with any high current dropped across it.

Finding a load higher than 100 MA would be a problem where a partial short or leaking path to ground is occurring from wiring or accessory fault. You would start pulling random fuses looking for it to drop pointing to the rouge circuit. A 5 Amp fuse doesn't mean it draws 5 amps, the circuit draws much less but the 5 amp rating is where it opens (blows) before wiring melts.

A good tip is when you connect the batt. cable how much of an arc is present? There often is a tiny spark, barely noticeable, where you might see it in a dark condition. That would be the stereo load as mentioned above. Gently touch the batt cable to the post. If it pops with a noticeable arc or flash, you have a serious drain happening. You don't need an ammeter for this and is easy to troubleshoot yanking fuses until it clears.

Edit: oops, I just caught LadynRob explains the series connection. He went from the negative terminal side which works as well.

I've seen this issue from sound system amps (that would be amplifiers) not shutting down from the headunit send and pulling serious power when "off".

Lady72nRob71

This check is not too accurate if you have an aftermarket amp or alarm or other electronic equipment.
These devices have large filter capacitors in them which act like a short when they are discharged, but more like an open once they charge up. The arc can be large, but after a second, they get charged and no longer draw much current.

White_Knuckles

^^ good point. A cap can be miss-leading from the charge cycle. Not knowing the posters situation, the suggestion was generic meant to use as an indicator of trouble.

With your comment, should they have a monster sound system, the whole thing should be isolated to eliminate a phantom load.

I had this problem with my car when purchased. The seller said everything was dandy. I found the batt. dead the next day and when recharged, it drained down overnight. When connecting the batt. terminal I noticed an arc and that the horn relay was pulling in. Tracing the wiring, I discovered the horn grounds were pulled off. The stupid cheap Grant wheel horn button was stuck so they had yanked the grounds preventing endless honkage. I isolated the horn ground and soon replaced the wheel with a high-end Grant with a proper button and cured the relay issue. That relay must have survived hours of being constantly energized. Good relay I guess?

Point is, arcs and relay clicks can make for a tell-tale story. Also cheap Grant horn kits suck. Do not recommend!

logizec

I jump started it this morning and took it for a small drive. Made it less than a mile and had to stop at a light, and it died. Had to jump start it again in order to drive back home. I am going to say that the alternator isn't working correctly (and will let the shop know too).

I bought a reman alternator for $50, so i'll have it changed this week. Hopefully this resolves my problem.

Miles71

What is the current rating of your existing alternator? It looks like some 93 could have 100 amps.
Amp meter:
Read the manual for your meter and follow the directions. The meter does not go “Across” the battery while in “Current / amp” mode. If you set the meter to “AMP” and then attach the meter the way you use a “Voltage” meter, the magic white smoke in the meter will be released or a blown fuse.

Set the meter in AMP mode to its high value, such as 10 amps for your first test (if it has a 10 amp mode). Turn everything off, Doors closed, keys out, etc. Then take a few readings. If you see less than 1 amp, disconnect meter and reconfigure meter for a lower amp scale for a more accurate reading. I do not know the exact Good value for your car, so let’s assume the “All off” drain is less than 0.1 amps or 100 milliamps or less is good.
Take notes of what values you see with everything OFF.

Then remove meter and connect battery as normal and switch meter to Voltage mode.
Volts with Key off.
Start engine; keep lights and all other stuff off. Take a new set of readings.
Volts engine Idle, Volts 1000 rpm, 1500 rpm, 2000 rpm.
Turn on Lights, heater on Low (AC Off),
Take a new set of readings with engine on and lights on.
Volts engine Idle, Volts 1000 rpm, 1500 rpm, 2000 rpm.
With a 100 amp alternator, at a stop light with Headlights on and AC Off, I would guess that you should never see below 12.0 at any time.
Also compare the reading on your Digital volt meter at the Battery with the Dash volt meter and see how closely they match. On my car, my dash meter gets its reading from the fuse panel, which is 0.7 volts lower than at the real battery.

logizec

Replaced the alternator this weekend.

After replacing the alternator, we jumped the oldsmobile. Took it down the road where it died for 5 minutes while warming up (died several times). Was able to drive it around after 5 minutes without it dying at all. Let it sit all night, and tried to start it in the morning. Dead.

Bought a battery charger last night. Charged it at 2A for 5 hours. Removed the charger, and the car starts! Let it run for a few minutes, and put in reverse to drive around. Car dies. Will not restart as it is below 10v according to my gauge.

I am thinking the culprit is the battery. The shop put in a used battery (mine was covered in acid). Could the battery be bad because it sat dead for a week?

MDchanic

If your battery shows below 10V, it's got a bad cell.

Did you pay for this used battery? Was it tested and shown to be good before it was installed?
That shop may owe you a good battery.

That being said, I would advise you to go get a new battery, and then make routine measurements to see how well the system is performing.

• Start with the car off, after it's been sitting a day or two. Measure battery voltage. Should be about 12.5.
• Leave the voltmeter connected to the battery. Crank and start the car. Voltage can dip to about 10 while cranking, but should come right back to 12.5 after she starts, and should then climb slowly over the next few minutes to about 13.5-14.5.
• During this time, revving engine should make voltage come up, then it should settle back down at idle. After those few minutes, once it has settled, revving it shouldn't make it come up.
• Once the car has warmed up and gone for a (daytime) ride, recheck voltage at battery and at alternator output post. Now put meter on battery, allow car to idle, and turn on all accessories (not flashers) - fan on High, Highbeams on, Rear Defrost on High, if so equipped. Voltage should drop, maybe as low as about 11, at idle, but bringing it up to about 1,500, maybe 2,000 RPM should bring it right back to 13.5-14.5V.

Once you've done all that, you'll know whether the charging system is working.
If it still has a problem, you need to connect an ammeter in series with the battery with the car off, read the current draw, and go around disconnecting things until the draw is zero - at that point you can selectively reconnect things until you find the leak.

- Eric

Lady72nRob71

Very well could be. When I saw "new battery" in your initial post, I thought just that.
Do you know how old it really is??
You could charge it ay 2A overnight out of the car and take it to a parts store to check on their tester.
If it had sat dead for a week, that could be a contributing factor. Once a non-deep cycle battery has run dead, its life is greatly reduced each time it happens.

MDchanic

Rob, you're familiar with electrical engineering to some extent, if I recall -

An otherwise good battery, even when badly discharged, will show somewhere in the 11-12V range with no load. Put a load on a dead battery, and, sure, the voltage will drop into the toilet, but no-load, a 12V lead-acid battery shouldn't set below about 11.5 (say 11 to be generous).

He says his battery is "below 10V," which means he's got a dead cell, which is unrecoverable.

I wouldn't waste time messing with it - I'd just replace it with a new one (this time ), and reinitiate troubleshooting.

- Eric

White_Knuckles

I'm not sure that a 10V drop absolutely indicates a dead cell unless there's some 2V per cell rule I've missed. A shop hydrometer (specific gravity) test will tell you the electrolyte and general cell's health. Too low of a number and she's toast.

I agree with Rob that conventional batteries will suffer a slow and painful death from excessive depletion. I now buy glass mat, premium (Johnson-Controls or Excide) and use a battery tender device to maintain the plates when storing the car. These buggers can take a beating and never let you down.

White_Knuckles

Sorry forgot to address the problem here. Got all theory nutty with the battery boys.

Okay let's go back to charging circuit 101. You say the car croaked simply engaging reverse? No matter what kind of condition the mystery battery is in, the car should maintain running even if the Alt. is loaded trying to recover the charge.

Charge or jump the car and then start it. When running, loosen and remove the negative batt cable. The car should continue running on the Alt. You changed the Alt. out, let's see if she's working?

Lady72nRob71

Batteries can fail in many ways.
Sounds like his did okay after charging, as the car started. I assume 10V was read after the car died. 5 hours at 2A is not much charge for a dead battery.
A load test and a let-it-sit test will determine the health of the battery.
Remove battery from car. Charge for 12-24 hours on 2A mode, disconnect charger and let it sit a day. Then take it to a parts store where they can load-test it. My bet is that it will fail. A healthy batter should be able to sit 2 weeks without much loss of starting capacity.

Electrical issues are very difficult to troubleshoot over the web...

stellar

If you need to depend on this car, I would not use a used battery and a $50.00 reman alt is a bit suspect too. Since you have had a few alts in there I will assume it is good. Dead in the morning and dead while running could be a very bad battery. Also see if there is a junction about a foot from the battery. A battery wire will go to this junction. This usually has a red cover on it. It is known to cause problems. They have high resistance connections and will sometimes melt the surrounding plastic. If you have an unusually high volt reading at the alternator post when the car is running at high idle check this connection. I am not sure if the 93 has this connection, but the 94 does. It is worth a look. if it is burnt it is not an easy fix. If it is bad it will become hot when the car is running.

MDchanic

It's actually about 1.5V per cell .

I'll PayPal the charity of your choice $5 if that battery is reading 9.xV ("below 10V") with no load and all the cells read good.



- Eric

oldcutlass

Eric you are correct a voltage with no load at 10v is a serious defect. The battery is probably toast. The rule of thumb is 2.1 - 2.2 volts per cell.


As mentioned above, get a know good battery, start the car, let it warm up, turn on the lights and disconnect the battery. If the car stays running the alternator is performing fine. The problem is either the battery or the wiring to it.

MDchanic

Am I old enough to claim "senior moment" when I said 1.5?

- Eric

stellar

I would advise against disconnecting the battery when the car is running. If the alt is not working there will probably not be any damage done, but it is still possible. If the alt is working damage may occur. If the alt is working you will get a voltage surge that can damage other electrical components like computers, modules, radios. Sort of like a lightning strike to your home damages the microwave. The battery acts like a big resistor and when it is disconnected the voltage will surge. Even if the alt is not working you may cause damage by the effect of field collapse. This will occur in any active coils like relays. Similar to the way an ignition coil works. Open the circuit and you get a spark at the spark plug. It was ok before the early 70's but I would not do it on anything later than that.

MDchanic

Stellar knows what he's talking about - he is an expert in charging systems.

If you follow my instructions above (or those of a number of others as well), you will gain more information about your charging system, with less risk.

- Eric

White_Knuckles

Oh man, I didn't catch we were dealing with a 93!! Sorry. The cable pull test is fine with my 60's flavor mechanical regulated system.

I thought we all had old timey stuff here?

oldcutlass

I agree to a certain point that this may happen, although very slim. He can also start the car with a known good battery and measure the voltage at the battery where he should read 13.5 - 14.5 volts when charging.

Miles71

We still have too many unknowns issues (Battery, Wires, Alternator or all?).
After you buy a new battery, write down the voltage before you install it in the car.
Start the car and check the volt meter again and write it down with the approximate RPM.
If your engine running idle voltage with all junk off is over 13.5V, then your Alternator is at least partially running.
Now you can take the car for a ride.
Do not drive until you have verified the alternator is over 13.5 with all junk off. Post your results and then start searching for other issues.

Until you resolve your charging / discharging issues, it would not hurt to leave the small 2A charger on each night.
Miles

logizec

Update.

Brand new battery as of last night. Let it sit all night, and it started up fine this morning. Drove it and within 5 minutes it died. Attempted to start it(took 5 minutes), and finally succeeded. Drove it around for a little bit longer and took it to a shop. The shop owner explained the problem to me like this: When you replace a battery in a car like mine, you have to let it run for 50-100 miles to adjust to the new battery (something about the computer memory). I drove it around my town for 20 minutes, and it ran perfectly fine..not dying at all. Stopped at the DMV to inquire about license renewal, was out of the vehicle for 10-15 minutes. The car died on me once on my return trip home (about 10 minutes), while stopping at a light. It fired right back up when i turned the key.


Is the mechanic bsing me? He said it was only a half hour worth of work, and it would be $70 in order to do. Does the battery need time to adjust to the new battery?

pogo69

could a bad crank sensor be the problem?

Lady72nRob71

Not in any way that you would notice, like the car dying.
Some cars will set non-critical trouble codes for checksum mismatch or similar but they will be invisible to you and will correct themselves when cleared. My Caddy does this.

Looks like you had 2 issues going on.

oldcutlass

If you can restart the car over and over after it stalls, lets assume your charging system is ok and there are other issues that now need attending to. The stalling issue is probably related to something else.

MDchanic

Yeah, have you read the codes out of the computer?

- Eric

logizec

From what I can recall, there are no computer error codes. I'll run it by advanced auto parts tomorrow and have them read my computer.

Edit/
I drove the car to work today, and had no problems. Was driving it home when and went to slow down at a night, the car shuts off. Won't start for around 5 minutes, and then starts. It seems that only cold effects it..once it's been running for a little bit it seems to run fine (minus a stutter when i press on the gas)

pogo69

if you have a fuel pressure gauge you may be able to rule out a fuel pressure problem. i know sensors (crank, cam) can give intermittent problems with stalling untill they totally fail.

pogo69

I havent had problems with camshaft sensors but i have had two oldsmobiles close to your year needing crank sensors for identical problems you describe....then again it is an oldsmobile so it could be just about anything up to and including mechanical nervous break down

White_Knuckles

I've experienced intake cam sensor fail (on a non-GM car) without any code(s) thrown. I think it hits so quick the error is not trapped in memory, it just croaks. May apply to crank position as well.

Electric fuel pumps also have this intermittent behavior. Start and die, start and die usually plays in. The long wait before restart is strange.

logizec

Quick update on the car!

The car runs perfectly fine now, minus the lack of heat(getting fixed today hopefully-seems to be a thermostat problem). However, i have a stuttering problem when the car is cold. For the first 5-10 minutes of a drive the car will have problems staying running while driving. Whenever i press on the gas, it stutters and sometimes dies. When it does die, it will not restart unless im holding the gas down while turning the key. It always starts when I do the above. After about 10 minutes the car no longer stutters, and runs perfectly fine. Ideas?

1970supremevert

see if you can check the MAF sensor, may not be able to get codes from advance that veh has a ABD 1 system, usually with ABD 1 systems you need to count how many flashes engine light with out starting engine,I would double check Google on how what to look for on ABD 1 systems good luck

White_Knuckles

Those first gen systems actually output data that can be viewed on shop diagnostic scanners or a notebook PC. I used a free program: winALDL. You can build a cable adapter or buy the setup on Ebay for $80. Check Engine Codes may be revealed counting flash blips but the diag. pulse code displays live in real-time with RPM and sensor outputs. I was surprised when the notebook showed several pages of needed data after hearing local shops say they don't have these monitoring tools anymore.

The '91 Chev truck, having a fresh engine, always ran sluggish and became horrid when cold. This was a TBI injection system. They are pretty complicated to dive in we found after changing several suspect parts with no fix. The OBDI data can be read live so you could spot a bad EGR or unusual O2 range for example. This thing had a timing problem. It turned out to be a vacuum device (MAP) that advances timing reading the vac level.

Also discovered from experimenting with fuel and ignition parts going in and out (for days!), somehow we fouled the plugs! The car still shuddered after the sensor was replaced. We stuffed fresh plugs in at the beginning of the nightmare and didn't suspect them. You might pull a couple and have a look? Sometimes it's the stupid stuff.

Rickman48

Few years back, had many of the same problems on a '69 442.
Turned out the positive cable was corroded internally, but looked perfect.
Replacement fixed everything - and hooking-up the groundstraps to the valvecovers.