I would drive and the first thing that would happen is the battery light would come on. Then my speedometer would shut off. Then one by one my Radio, AC, courtesy lights, windshield wipers, and pretty much every other electronic device shuts off. It is a brand new battery just got it last month.
I would drive and the first thing that would happen is the battery light would come on. Then my speedometer would shut off. Then one by one my Radio, AC, courtesy lights, windshield wipers, and pretty much every other electronic device shuts off. It is a brand new battery just got it last month.
Do you have a multimeter? Make sure the battery is fully charged, then check the battery voltage with the car running. It should be around 14-15v.
if you alternator is dead, you'll need to have your battery recharged because it's being drained while your engine is running if the alternator is bad. another way you can test if it's the alternator is to: start the car then pull the positive/red terminal off, if car keeps running alternator is good. if it stalls then replace.
same symptoms in my truck, i luckily got it ovr to the side cause i was on a highway, sure enough thats what it was. had to get the battery recharged to drive to auto store to test.
if you alternator is dead, you'll need to have your battery recharged because it's being drained while your engine is running if the alternator is bad. another way you can test if it's the alternator is to: start the car then pull the positive/red terminal off, if car keeps running alternator is good. if it stalls then replace.
Never do this... This could just cause even more problems. The electrical system relies on the battery to keep a constant and clean voltage. Connecting and disconnecting a battery will cause a spike in voltage and could damage a number of electrical components. Just check the voltage with a multimeter while the car is running.
Please don't disconnect the battery of a running car. An alternator adjusts it output by sensing a varying field voltage. If you pull the battery lead you can experience a very short voltage spike up to ~50 volts.
I see this was mentioned earlier. It is certainly worth saying again. Quaraxkad is absolutely correct. Under the right circumstances you could take out the rectifier and other very expensive components downstream.
In addition when replacing the alternator, charge the battery before installing the new alternator. I cannot emphasize this enough. The alternator is meant to maintain the charge in the battery not to recharge it. I have written a long post about this in the past.
well, I did get it to advanced auto parts and tested it with a multimeter. alternator was bad. replaced it. and replaced the battery. But the same thing is happening. any ideas?
well, I did get it to advanced auto parts and tested it with a multimeter. alternator was bad. replaced it. and replaced the battery. But the same thing is happening. any ideas?
Did you get the alternator tested or just assume that it was bad? Did you install your alt. belt to the correct tension?
Quaraxkad:
I got it tested at advance auto parts and they said the alternator wasnt putting out anything. And I didnt install it myself, I took it to tuffy to be installed so I'm sure they did it right.
Dave: Ill get you some readings. Im about to get it towed back to tuffy,
Here is what I am about to do: I am going to have the alternator replaced (its still under warranty) and AAP is going to reimburse me for the labor I paid at Tuffy. The battery is still under warranty so I am going to have that replaced also. Then I will have tuffy install both at the same time. Because I found out that the first time, They installed the alternator and forgot about the new battery in the trunk so when My cousin left the shop they called him back so he can come back to put the new battery in. The old battery had a bad cell. So I am assuming that the bad-celled-battery messed up the new alternator.
What a confusing mess. Let's do this. Only replace parts that are tested and found to be bad. Next, a battery with a dead/shorted cell will not wipe out the alternator. I have to wonder about a shop that installs parts and does not test function when they are done.
If your old battery has a dead cell, confirmed by hydrometer test vs. word-of-the-week, then replace it. Make sure it is fully charged before proceding to the next step.
Let's diagnose the damn alternator and figure what's going on. You could have poor brush contact giving intermittant charging. This could escape detection of a casual mechanic not carefully testing your alternator. Slap the whole thing back together and report back.
alright sit down and get ready for your blood pressure to skyrocket.
I tested the battery and the charge was low so I took it back to Sam's club and they charged it for me. I have the printout to show that the battery is now good and charged.
So I take the battery back to the car and connect it. car starts, and we connect a mutimeter to it. and What does the printout show? That the alternator is not putting out any power to the battery. All fine and dandy up until now.
So I take the alternator back to advance auto parts and they bench test the alternator. and guess what? the alternator tests just fine. But I ask if they can just replace it for me just in case. So he did. So now Tuffy has my car with a brand new alternator, a brand new and charged battery, and new alternator belt. They will install it first thing in the morning.
BUT: I think there might be something else wrong with the car. not the alternator or battery, I think there is some kind of fuse or wire or connection or relay or something like that. I asked Tuffy to look for anything that looks abnormal and two of the technicians spent three hours straight just inspecting things and sticking a voltmeter in every wire and fuse they could possibly find. Nothing. any suggestions lol?
Oh and I have the printouts but they are really big (32MB) so I can not attach it on this forum. (100KB is kinda low dont you think) so I can email it to anyone if they want to see them.
No jump in BP yet. If the battery is good and the alternator is good then the problem is somewhere else. Eight years of college leads to that statement. There is a 120 amp fuse and three others asociated with the charging system. This could also be an open in the field wire. Tugging and twisting of the wires at the alternator during removal/install could account for that.
Three hours to diagnose a charging problem seems excessive. This is especially true since they didn't find the answer.
I hope your mechanics are armed with a service manual and a wiring diagram. The Acura service manual is excellent for electrical diagnosis. You may be in the change mechanic mode soon. I could send you the 94 diagram and procedure but I think there is too big of a chance for error.
If it were me I would check for battery voltage at the alternator output terminal. We know that is hooked to the battery all the time. Next I would hook a wire from the battery to the field lead on the alternator. This would bypass the entire field wire circuit. If the alternator is good it has to charge under these circumstances. Period. Basic invasive diagnosis.
In my 94 Coupe manual on page 23-117 there is a simple diagram of the charging circuit. Fuse #22 comes off the ignition switch. This looks like the voltage sense wire. It also flows through the charge light. When there is no charging is the battery light on? It indicated a difference between bus voltage and alternator output. If the alternator output drops off a potential difference exists between the bus and the alternator, illuminating the light.
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