NewHilux.net

I've started installing a Projecta IDC25 DC-DC charger and can't decide if I should connect the blue ignition wire or leave it open?

On a previous thread (viewtopic.php?f=121&t=26010&start=200) rjo89 said "I left the ignition wire open and it appears to be working fine, charging and isolating as it should. Any questions feel free to ask!"

Why would you leave the blue ignition wire open if the manufacturer recommends it be connected?

Cheers and thanks,

Mark

The blue wire is only needed if you are unlucky enough to have a "smart" (dumb) alternator with variable voltage that can drop below the 13.4V automatic switch on point in the device.

When the blue wire is connected it shifts the internal switch on and off points to lower voltages to ensure it comes on when the alternator is on, but this is not ideal as it can also run your main battery down lower (11.9V vs 12.8V) after the vehicle is turned off before it disengages.

Hilux alternators are not fully "smart" (dumb), they "temperature compensated" only and don't vary much. Mine sits all day at 13.6volts and works fine with my Redarc SBI12 which has a switch on voltage of 13.2V.

As a comparison I also have a Subaru diesel which does have a fully dumb alternator that regularly dips below 13V and plays havoc constantly switching the SBI12 on and off and so has to have it's blue wire connected.

FYI all the switching voltages are in the table in the instructions.

Worst case is in the future if you ever notice it is dropping out then at that point connect the blue wire

Thank you Bushwalker8, in the short term. I'll monitor the voltage and decide later.

Cheers for now,

Mark