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Low Voltage Issue

PostPosted: Mon Nov 16, 2009 3:19 pm
by SagaTiba
I have a Next Step 12P and I'm having an issue where I'm only getting 13 Volts while charging. I'm also only getting 50 Amps, degrading to 30 amps during charge from a 120 Amp alternator. I have a house battery bank with 300 AH. It takes forever to get the batteries charged.

I'm getting the following signals
Green Light: 2 sec on, 1 sec of (bluk)
Red light: 1 sec on, 1 sec off (can't turn field off)

I did the troubleshooting measurements and got normal readings, with a bunch of abnormal readings.Following are the abnormal readings:

Parallel: Ign Off: 5.1, Ign On: 5.1, Engine Running: 0.5
on/off Ign Off: 0, Ign On: 12.8(battery voltage), Engine Running: 7.18
Field: Ign Off: 12.8, Ign On: 12.8, Engine Running: 13.6
T+ Ign Off: 1.4, Ign On: 4.6, Engine Running: 4.4

Re: Low Voltage Issue

PostPosted: Mon Nov 16, 2009 3:34 pm
by Coulomb
Some of those problems might go away if the on/off voltage was appropriate when the engine is running. Something is loading the ignition circuit, or maybe the ignition switch has a problem.

The voltage on the field, 13.6, is full field, so the alternator should be putting out maximum Amps.

Re: Low Voltage Issue

PostPosted: Wed Nov 18, 2009 1:56 pm
by SagaTiba
I cleaned the terminal at the ignition and now I am getting the full 12 volts and 13.4 volts at the on/off terminal.

However, nothing has changed regarding the charging volts and amperage. It is still giving me the same error and I'm still only getting 13 volts charging.

Any ideas?

Re: Low Voltage Issue

PostPosted: Thu Nov 19, 2009 11:45 am
by Coulomb
With full field voltage the batteries are either seriously discharged, or the alternator is not producing many Amps.

Re: Low Voltage Issue

PostPosted: Sat Nov 21, 2009 5:32 pm
by SagaTiba

The alternator registers 14.4 volts at the back when the engine is running. What explains the blinking red signal sayin that the regulator is putting out too many volts when in fact it isn't putting out enough?


Re: Low Voltage Issue

PostPosted: Thu Nov 26, 2009 3:38 pm
by Coulomb
What alternator do you have?

Re: Low Voltage Issue

PostPosted: Wed Dec 09, 2009 10:22 am
by SagaTiba
I don't know exactly what alternator I have. There are no markings on it other than the fact that someone has written "14V 120 Amps" in black marker on the side. The alternator has a small black button regulator on it with these markings "1 197 311 02". Does it seem odd that there is a built in regulator and also the Next Step Regulator in the system?

Also, the more I use it, I notice that the amperage drops significantly after about 30 min of putting out 30-40 amps. It then drops down to 14-19 amps after only 30 min of bulk charging, with the Next Step still indicating Bulk Charge on the green light. This is after the battery bank is so drained that it drops down below 12 volts. I can't imagine that a 300+ Amp hour battery bank is needing to have the charge stepped down after having 20 amps dumped into it after it has been drained so much. I'm wondering if I have a bad battery in my bank now that is preventing the bank from taking a charge.


Re: Low Voltage Issue

PostPosted: Wed Dec 09, 2009 11:44 am
by Coulomb
There should never be a built-in regulator when an external regulator is used.

Bad batteries will give you the symptoms you have. You need to read what constitutes a full battery listed as a "must read" topic.

You should also read the primer on testing batteries - the overnight test in particular.

There is also alternator troubleshooting guides here: