Smart regultor

[jaramanpotter]

We have been having voltage runaway with our alternator charging thru a Ample Power Next Step.
History - system in place for 10years. We live onboard 24/7. Problem started Jan 2014. We replaced a fuse on temp sensor - it was not blown but was a bit wobbly. This worked for a couple of days. Then bypassed that fuse bax as it was a new installation - OK for a couple of days. Worked thru the provided troubleshooting guide - all results normal. We dicided to replace the regulator as it was about 9years old. New one fitted in Feb- NS2. All was well until last week. Now voltage runaway is constant when running engine. All the values on the trouble shooting guide are normal. Have tried covering solar paanels to allow batteries to be dow a bit. No change. When large load is applied the battery waring alarm sounds.

[d design]

Sounds like you have a voltage drop somewhere that the regulator is sensing?
Whats the condition of your batteries? make sure all connections are clean.

[smac999]

"when large load the warning sounds."

sounds more like under charging to me. as voltage normally drops as more load is put onto the batteries. your alt might be dying and not keeping up any more.

have you measured voltage at batteries and at alt. posts? or are you just listening to the warning buzzer and guessing?

measure both of these with small loads and big load.

also measure the field voltage.

where is the battery sensor wire connected to? battery or alt?