National Luna Intelligent Solenoid Problem

[Awhatley]

Hi

Please read my question to the end before reaching a conclusion. It's quite specific.

I have a National Luna Intelligent Solenoid system in my Toyota Hilux. It charges a brand new 105AH Deep Cycle Battery for my fridge. The Intelligent Solenoid kicks in after 5mins as planned, but then it kicks out again after 3mins before starting the 5min/3min cycle again.

I have connected everything strictly according to the instructions. I have tested the power at various points and it's all fine. There's a constant 14v coming from the alternator. The Battery is brand new and the charge remains at above 12.4v. Even when I unplug the fridge, so there's no drain on the charger, it does the same.

I though it was a faulty Intelligent Solenoid so replaced it, but the new one is doing exactly the same.

Why is it switching off.

Thanks

Allan

[ChrisF]

Hi Allan

WELCOME to the forum !


The unit is supposed to shut down and wait 5 minutes after the engine was started - OR, stating it in different way - each time it looses its signal power (from the ignition) it goes back into the 5 minute cycle ...


But you say you have already swopped out the NL unit .. thus highly unlikely that you have a second dud NL unit.


From what I understand .... okay, I checked their website - http://www.nationalluna.com/intelsol.htm" onclick="window.open(this.href);return false;
Click on the "Download Instructions" link, have a look at the Top Right corner - "Unique Features".

Thus it would appear your alternator is dropping below 12,7V. OR at least your NL unit thinks this happening !


It is VERY easy to have one bad connection in such an installation, and under load it causes a voltage drop. - thus you DO measure the correct voltage at the battery, but the NL unit sees a slightly lower voltage, just low enough for the unit to "think" the battery voltage is below 12,7V.


I would recommend you check and possibly re-do each and every lug and fitting - crimp and solder it, make SURE there are no bad joints.


Hope this solves your problem

[Johan Kriel]

It also cuts out if it sees no battery, thus ,yes, poor connection or if the battery cant be charged!

[isinyoni]

Yup, I agree. There is not enough info make a thorough diagnosis but this is certainly the most obvious.

Alternately pick up the phone and speak to someone at NL. They are very customer friendly.

[Bosfebok]

As far as I can remember, if the common voltage over both batteries goes below 12.7, then it cuts out, and starts the cycle again. It also cuts out if the common voltage goes above a certain voltage...can't remember.

Agreed with the previous posts, either loads or a bad connection. A bad connection between the batteries (positive or even earth) can screw up the common voltage reading quite significantly.

Start your vehicle and do not switch on any loads, let it kick in. Measure the voltage at your main battery with a voltmeter, and at the back and repeat till it kicks out again. Check that you do not have a voltage drop on the wire to the second battery.

Hope you come right.

[subok]

What if the 2nd battery is fully charged? Does the solenoid not switch off?

Sent from my SM-N910H using Tapatalk

[Bosfebok]

http://www.nationalluna.com/Datasheets/ ... ctions.pdf

It describes the fault conditions. Seems I had it wrong. It measures the voltages of the main and auxilliary batteries seperately. It will cut out if the main battery is below 12.7V.

[ChrisF]

http://www.nationalluna.com/Datasheets/ ... ctions.pdf

It describes the fault conditions. Seems I had it wrong. It measures the voltages of the main and auxilliary batteries seperately. It will cut out if the main battery is below 12.7V.

OR if it THINKS the main battery is below 12,7V - thus my comment on checking for a bad connection ....

very easy to start chasing your own tail with these faults !!!!

AT the first battery it may very well test at 13,8V, but one bad connection and the voltage will drop AT the NL unit at the first sign of high current draw .... thus the start and stop ....