New Battery and New Alternator, still less than 12 volts from battery, what else?
#1
New Battery and New Alternator, still less than 12 volts from battery, what else?
Hi, I recently replaced my battery and alternator in my 66 Dynamic. The battery is still only putting out less than 12 volts (11.2). The car won't start after I turn it off after jumping it. The GEN light was on before I replaced the alternator, but is not on any longer since I replaced it, but the battery is still below 12 when running. What else could it be? The voltage regulator? I bought the car a year ago. It was completely rebuilt with everything brand new inside the engine compartment including the battery, alternator, and voltage regulator (attached to the firewall). Before I give up and take it somewhere on a wild goose hunt, any thoughts on what I can do to troubleshoot it? Thanks!
#3
Charging system description and troubleshooting begin on page 12-4 of your Chassis Service Manual.
The key test here is to disconnect the regulator plug from the back of the alternator and hot-field it by connecting the F terminal to the battery (+) and then run the engine at idle, slowly increasing RPMs while watching the battery voltage, with all accessories turned on at their highest settings (do not allow battery voltage to go higher than 16V).
If the alternator supplies voltage as it should, then the problem is your regulator (or connecting wires or terminals).
Read the CSM, then test your charging system as recommended there.
- Eric
The key test here is to disconnect the regulator plug from the back of the alternator and hot-field it by connecting the F terminal to the battery (+) and then run the engine at idle, slowly increasing RPMs while watching the battery voltage, with all accessories turned on at their highest settings (do not allow battery voltage to go higher than 16V).
If the alternator supplies voltage as it should, then the problem is your regulator (or connecting wires or terminals).
Read the CSM, then test your charging system as recommended there.
- Eric
#4
Have the alternator checked where you purchased it... Just because it's new or remanufactured doesn't mean it is putting out as it should... Also the voltage regulator can definitely be suspect even if previously replaced...
#6
#7
Not giving you the fish but teaching you to fish :)
I had a similar issue in my Alfa with my refurbished alternator which was setup with an external regulator (since the internal diode pack was blown).
http://www.teamhealeytexas.com/Techn...Wiring%201.htm
I followed instructions and connected the sensing wire to the correct location (earlier it was connected to the alternator output. it is where the voltage is highest. so I connected it to a place where the voltage is the average of the system)
Now the voltage at the battery is 14.2V even running at full load.
http://www.teamhealeytexas.com/Techn...Wiring%201.htm
I followed instructions and connected the sensing wire to the correct location (earlier it was connected to the alternator output. it is where the voltage is highest. so I connected it to a place where the voltage is the average of the system)
Now the voltage at the battery is 14.2V even running at full load.
Last edited by kuseetha; June 27th, 2017 at 10:08 PM.
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jpaulwhite
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December 19th, 2011 07:26 AM