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Intermittent Charging Problem

PostPosted: Wed May 09, 2012 12:03 pm
by richlem
We are having an intermittent charging problem The system is 11 years old and made up of a house bank of 4 - 6v batteries (replaced 2009), a 12v starting battery, a 125 Amp alternator (checked 2012), NextStep 12P (S/N 420) regulator , EMON2001-H1 Monitor/Controller, Parallel Solenoid for starting battery charging. The 120v charger is TruCharge 40A (Replaced 2009).
The system design is based on your Drawing AT9610287, Alternator output is connected directly to the main PD bus, no 1-2-Both switch involved. We use the Parallel line on the regulator for the Solenoid and the ABS line on the regulator is connected to EMON, the Lock line is not used.
Last fall as we were getting ready to move the boat for hauling, I noted that the output voltage was at 16.8 volts. I shut down the engine to investigate but did not have time so we haul at our summer yard. Over the winter I had the alternator checked; it came back with no problems.
This spring, as I was doing the voltage checks in the Troubleshooting guide I saw that for the most part the battery voltage was 14.3v with the engine running but for about 1 minute it went to 16.8v.
Here are the readings without the spike:
Signal Ign off Ign On Eng Run
House Bat 13.33 13.34 14.24
Parallel 13.28 13.34 0.83
Off/On 0 13.27 14.18
Ground 0 0.02 0.01
B+ 13.56 12.95 14.55
Field 0.04 12.7 3.5 to 3.8
Alt Gnd 0 0.02 0.02
Lock 0 0.01
Bat Volt 13.25 13.31 14.45
T- 0 0.02 0.02
T+ 0 2.8 2.9
ABS -7.43 -7.43 -7.45
Lamp 0 0.02 0.35

Unfortunately we did not get readings with the spike. We ran the engine for about 30 mins and did not see the spike again.
My next step is to clean all of the wire terminals to be sure I have good connections.
Anything else I should be doing? Anything in the voltages above to be concerned with? Is it likely I have an intermittent problem in the regulator or should I be looking elsewhere?
Thanks for your help
Rich Lemieux

Re: Intermittent Charging Problem

PostPosted: Mon May 14, 2012 10:02 am
by Coulomb
Intermittent problems are almost always connections.

Don't forget to clean the fuses and holders.