low voltage
Thread Starter
Racer
Joined: Sep 2005
Posts: 336
Likes: 0
From: staten island ny
low voltage
i have being having to jump start the car 2 days in a row i notice the voltage dropping below 10 once i have accessories on if i put the dfroster on it will drop below 10 could this be a bad alternator or a bad batterie
thank you
thank you
Team Owner
Joined: Jan 2003
Posts: 20,277
Likes: 236
From: Summerland B.C. Canada
7th Gear
Joined: Nov 2008
Posts: 7
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Do you have a digital multimeter? If so, you can easily check the voltage the battery is receiving at engine idle. Should be AT LEAST 12 volts.....maybe 14 or slightly higher if the battery is not fully charged and the alternator/regulator are doing their jobs. This DOES NOT mean the battery is OK, just how much is coming through the charging circuit. Also check the voltage out of the back of the alternator. If it is below 14-14.5, then it is likely the culprit. If is reads at 10, for example, you have a weak alternator, probably a diode or two burned out. If it is OK and the battery is still good but not receiving the proper voltage, then you have voltage drop somewhere in the system. An often over-looked problem is grounding within the system, especially around the battery or at the starter relay. Check ALL your connections. Please let us know....
Team Owner
Joined: Jan 2003
Posts: 20,277
Likes: 236
From: Summerland B.C. Canada
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Engine running, a voltmeter on the battery terminals should read 14.7 volts engine cold and this will drop to 13.7 volts when the alternator gets to its operating temperature. It sounds like your alternator is not charging the battery and you should then see the red battery symbol light on the dash. The dash voltmeter reads 0.3 volts low due to the voltage drop across the ign sw contacts. Also, the dash voltmeter reads low if the engine is not running and/or the alternator is not working. You can take the alternator off the car and have it tested at a parts store. When you take the alternator out, measure the resistance from the alternator output wire to the battery positive terminal. Your ohmeter should read the same resistance as touching the ohmeter probes together. If high resistance, you have a blown fusible link in the alternator output wire.
Thread Starter
Racer
Joined: Sep 2005
Posts: 336
Likes: 0
From: staten island ny
low voltage
after checking all connections i found that were the positive wire that bolts to the alternator was broken internally in the alternator and got my self alternator and new battery knowing the one i had i killed my voltage once the engine is warm 13.7 to 13.5 big diffrence from 12.8 i notice too the voltages stays steady no more up and down
know that i got everything resolve i might be able to enjoy the new 3.07 rear i put in 2 weeks ago
thank you
4 your guys help
know that i got everything resolve i might be able to enjoy the new 3.07 rear i put in 2 weeks ago
thank you
4 your guys help
