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While driving my son's 87 coupe to work yesterday the radio suddenly quite playing and went dead. I then noticed the dash lights slowly growing dim. I also noticed the traction control light was being displayed. I first thought a fuse had blown and continued on for about a mile. Soon the car started to sputter as if it was not getting fuel. I pulled into a convenience store and called my daughter to give me a boost with my cables. It started right away and I took it to a mechanic that was close by. I asked him to check the battery and he did. He told me it was the cheap Wal-Mart battery and it was showing no output. I then took it to a service station close by and bought a new NAPA battery. I drove it for the rest of the day and had no problem until later on in the evening. The same thing happened with the new battery. Anyone have any ideas? I am suspecting the alternator is not putting out enough power to the battery. I checked the belt and it seems tight. All of the cables seem tight also. Please help!
Look at the dash voltmeter, engine cold and running, it should read about 14.3 volts and as the alternator gets to its operating temperature, the dash voltmeter will read 13.3 volts. Anything under 13.0 volts and the alternator is not charging the battery. Also you should have noticed that the red battery symbol light on the dash was on indicating that the alternator is not charging.
Charge up the battery with a battery charger, don't expect a new alternator to do it, you will just shorten its life. Alternators were not meant to charge up badly discharged batteries.
Hook up a voltmeter to the battery and take a look at the voltage as you start the car. It should jump to about 14 volts and stay there. If not, measure the voltage at the thick red wire on the back of alternator. It's under the rubber cap and held down with a bolt. Plug the other lead of voltmeter to ground while engine is running. If same reading of no increase, the alt is bad. If higher voltage is there, trace the wiring between alt and battery.
Look at the dash voltmeter, engine cold and running, it should read about 14.3 volts and as the alternator gets to its operating temperature, the dash voltmeter will read 13.3 volts. Anything under 13.0 volts and the alternator is not charging the battery. Also you should have noticed that the red battery symbol light on the dash was on indicating that the alternator is not charging.
Charge up the battery with a battery charger, don't expect a new alternator to do it, you will just shorten its life. Alternators were not meant to charge up badly discharged batteries.
I noticed after switching the indicator from engine coolant temp to volts that it only read betweed 8 and 10 volts. Would this be an indication that the battery is not being properly charged? I got a quote from NAPA on a rebuilt alternator for $107.00. It would appear very easy to replace. Looks like all one must do is remove the belt and unhook the electrical supply. Any pointers that might be helpful would be greatly appreciated.
^^Yes, that gage should read 14.4 or so......nothing like 8-10.
Yes, alternator is very easy to replace yourself, don't pay for it to be installed. If you know how to take off your serpentine belt then you should be fine. Just take off everything that is in the way....nothing is critical in that area.
Just make sure you disconnect the battery prior to starting.
^^Yes, that gage should read 14.4 or so......nothing like 8-10.
Yes, alternator is very easy to replace yourself, don't pay for it to be installed. If you know how to take off your serpentine belt then you should be fine. Just take off everything that is in the way....nothing is critical in that area.
Just make sure you disconnect the battery prior to starting.
Thank you all for your input. I am sure it is the Alt. I will replace it on Tues. when it comes in.