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I've been trying to hunt down a major electrical gremlin in my car, but things just seem to keep getting worse.
When trying to start the car, it is 100% dead. No lights, to door chime, dead. The battery will charge to 13 volts on a trickle charger but when I connect it to the car the reading drops to near 0. Yesterday I hooked it up after cleaning some electrical connections and noticed a smell, sizzle sound, and heat coming from the battery (and immediately disconnected it).
So far I have cleaned up the battery wires at both ends, including major grounds, starter solenoid connections, alternator connections, and replaced the alternator ground cable. Checked, cleaned and replaced any suspect connections to the 25 Amp fuse and the positive distribution block on the drivers fender. I've also replaced the ignition switch, and cleaned the connections at the ICM (Ignition control module/power stage).
I'm not sure where to go from here. Replace both battery cables? Replace the starter and solenoid? I'm operating on the assumption that this must be an issue with the main power system of the car, as opposed to say a grounded oxygen sensor or speed sensor wire, since battery voltage drops as soon as the battery is connected.
Please help! What is the vampire that is sucking the life out of my car? I want to drive and visit my 90yo grandmother for Thanksgiving!
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Disconnect the pos bat cable and then connect a 12v light bulb between the bat post and the pos cable. If you have a short, the light will be very bright and the battery will still be happy. Play around with connections and cables until the light goes out. You have found the short when the light goes out. If something is on, clock,dome light , etc., the light will glow dimly as it should.
Happy hunting Tom
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Hello,
I agree with your more simplified method of using the on and off light bulb if you are not familiar with a multimeter.
The bulb will limit any current draw is the big helper here if there is a big short.
Good thinking you have done for him.
Phil
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Thank you guys, for all your help. The problem has been solved.
It all started out with intermittent no crank issues, but at the same time a door has been left cracked for a few days and drained the battery. In checking and cleaning all of the electrical connections I inadvertantly created a short at the alternator which made things worse and really fried the battery. With the short repaired and a new battery delivered and installed (thanks AAA) I'm up and running. And with a new ignition switch installed, my intermittent to crank issue seems to be in the past.
Thanks for all your help brickboarders, especially Machine Man Phil! It's always more complicated when you have multiple issues going on at once. It's always nice to have Brickboard to ask questions and bounce ideas around. Now I get to go have Thanksgiving dinner with my grandmother who turns 90 today!
Happy Holidays.
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Hi,
Glad you got it fixed!
Say, could your Grandmother happen to be Ann Turner Cook?
She is was the original Gerber Baby in the late 1920's! She also just turned 90 on the 21st.
Wow, what a coincidence that is.
Hey, slurp up some extra gravy on the stuffing for of all of US!
Thanks and yum!
Phil
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Sounds like your battery is toast..
--
Post Back. That's whats makes this forum work.
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Agreed. You maybe able to read "normal" volts but all of the amps have jumped ship. The short you are looking for is inside the battery. IMO.
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Hi,
Boy, sure sounds like a good story that is "brewing" on a battery is possible if one that heats up that quick!
How did you get that sensation that's it's heating up unless you heard it boiling inside? That would not necessarily cause heat but produce lots of hydrogen gases in a short time.
Speaking of a short, that would take a tremendous conductor across the posts.
A bad cell could explain some of total zero volt output reading triggered by a auxiliary current path to dissipate some of that energy. Everything gone from one side of the circuit or the same as putting both leads on one side.
I would seriously look at the big cables as mentioned by, our very own cookie man, Mr. Nabisco.
When starting the engine the voltage should hover around nine volts, not zero.
You should remove the cable from the battery positive post take an ohmeter check to ground and get a "no" reading at all.
If not and get some number "close to" 0.0 you have a bare point on a wire or terminal shorting. There also can be some shorted alternator diodes as they can drain a battery.
There also could be an issue with the connection down on the starter/motor solenoid terminal. This is the mid point between the two, the other being to the alternator.
You can check from the mid point going each way. Just a slight pain to get to. You will want keep the cables disconnected when flopping around a wrench down around there. Just removing the negative post cable first, during any work, eliminates all the sparks.
One way or the other it is a direction for that amount of current has to go to get out of that battery. The wires have to be large enough for it total smoke some them and these are not fused on most cars because of the amount of current varies so wildly during cranking temperatures. Short term activation is 150 to 300 amperes as possibilities.
Yep something that big will be found if you just leave it cooking!
Phil
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Thanks for your responses. I have a few questions about exactly what you are saying.
"You should remove the cable from the battery positive post take an ohmeter check to ground and get a "no" reading at all." Are you saying I should measure between the bare positive post and the grounded negative post out the positive post and the positive cable?
When you and Mr.Nabisco mentioned the big cable running under the engine, are you referring to the alternator to starter solenoid cable?
"There also could be an issue with the connection down on the starter/motor solenoid terminal. This is the mid point between the two, the other being to the alternator. You can check from the mid point going each way." How would I check from the midpoint going each way?
"How did you get that sensation that's it's heating up unless you heard it boiling inside?" The battery had been hooked up for a few minutes while I got in the car to check if it would start up. When I went back to the battery I first noticed an odor, immediately followed by a sizzling sound as if it was boiling inside, then as I held the battery to disconnect the leads, my left hand felt a good amount of heat on the vertical face between the terminals.!
I guess I will start by taking the battery in to be tested tomorrow morning. I've checked so much of the wiring I'm running out of ideas other than just replacing all the battery/alternator/ground cables.
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Hi,
You are going to be checking out the cables themselves. You will unhooked them from the battery completely.
I would unhooked the alternator's big red wire as well.
We will concentrate on the positive side of the cars system.
The ohmmeter is going to apply its own battery voltage through the cable from end to end.
It will convert that voltage reading into a resistance reading. A good cable will read a very low number almost all zero's. Like 0.08. A very low resistance or a short is the same as if the leads were held together.
The meter number should "not change at all" if you go from one end of a positive side cable end with one lead and the other lead touching bare metal on a grounding spot on the car.
The needle should not move on an analog meter and on a digital meter, it will show only the numeral "one." Like 1. And blink.
You want to see an open lead reading "to ground" on positive side cable when unhooked like this.
This is done with the leads on each end or from the mid point at the starter as you just said.
This way you divide the problem in half each way to the ends of the cable.
If there is a bare spot touching ground some place it will be on one or the other from the middle if you have to break it below.
The ohmeter is not very accurate to tell you how much resistance there is on very large cables. In this case of troubleshooting it's not necessary. You are looking for a direct short and hopefully on one side of the starter. Up to the battery or over to the alternator via under the engine.
You can also check the alternator stud to a ground or its housing if there is a cable on the housing going to the engine. There has to be one on there for the cluster warning light to work. That build in the cluster and gives the exciter diodes a little tickle or jump start through the rotor so the regulator can take over.
When the alternator outputs a small voltage, it opposes the battery voltage coming in from the light and it goes out.
It does not take much to turn the light out. So, it does not mean all is working great as these are called idiot lights
A dash type voltmeter is your best indicator, as it will tell you how much more above the battery voltage, the regulator is giving to the "SYSTEM."
A fully charged Battery is 12.65 and it needs at least a .5 volt to 1.5 volts above that to keep a battery maintained.
When get things straightened out take voltage readings on the battery posts with various items on in the car to see if the charging system is up to a 13.2 to even 14.2 volts on a semi to fully charged battery.
If you do not get good voltage readings all is not lost with just an alternator.
Sometime excessive corrosion inside terminals or under insulation of wires can cause a high resistance or voltage drop. This will throw off the feed back and output of the alternator.
In these cases there is another way to use a voltmeter to find out and where this can be in a cars system. Of course that is another chapter in troubleshooting for different reasons.
A multimeter is your friend because it can see electricity. That is, when you understand how to use the leads and the function dial.
It make working on these parts of the car more fun than just knuckle busting.
Thanks for the feed back. It's nice to know you are on it.
A Turkey Dinner is a good motivator.
Phil
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Did you check the main power cables for wear, cracks or shorts?
Isn't there a larger wire running under the motor that can cause problems?
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