The blue wire...

Hi Blue.
i have a redarc installed by auto electrian. you want me to take few pics and email to you, if yes give me yr email n i'll send some over.
cheers steve

Gday Blue,as I understand it ,its so if your starting battery goes flat you can power the blue wire and it will link the aux battery to the starting battery to get you started .You can also link the two batterys together while winching,I think some people have a switch in the cab so they can link batterys at the flick of a switch.Ive got the blue wire floating free on mine ,if I need to link them Ive just gotto hook it up to +.
Cheers Nick

My understanding is that this wire needs to be grounded through a momentary switch for the override to operate. While the switch is pressed the batteries will be connected.

Hi,

The Blue wire turns on the solenoid so the aux battery is connected and therefore overrides the smart circuitry within the Redarc that turns it off at 12.7v in normal circumstances. It is an optional connection and does not need to be connected.

The wiring diagram I have clearly indicates you need to apply +12v to the blue wire to power up the solenoid if you choose to do so. It also states "Use a dash mounted momentary spring return switch to connect the Aux wire to the postive of either battery to activate the solenoid ..."

Redarc provide excellent customer feedback and have talked me through several dumb questions I have asked, even providing drawings to help me with my out of the ordinary setup - 24v HJ61 Landcruiser with Redarc Voltage Equaliser and Smart Start solenoid powering an aux battery that is mostly out of the vehicle and connected only for trips away (due to lack of space to permanently mount it).

I hope this is useful.
Tim

Mad Dog is right on the money. The "new" redarc needs the blue wire connected to +ve of the aux battery (via a switch) to overide the solenoid. The "old" redarc required a wire to only be grounded to overide it.

Redarc made the change as if you have a flat main battery and want to bring in the aux battery, when you grounded the wire it required power from the main battery to close the solenoid. But if the main battery is flat, it cannot close the solenoid...

On the "new" redarc, the blue wire goes the the aux battery and so, when the main is flat and you want to overide the solenoid, the aux battery provides the power.

I got this info direct from redarc (great customer service) and they made the change in response to complaints from 4WD's that the overide didn't work when the main battery was flat. Again, great manufacturing response to a problem.

Cheers

Captain

PS. I have no affiliation with redarc - just like there products!

I've recently wired up my new Redarc unit. Connect the blue wire to one contact of a push button switch (in the cab) & the other push button contact to the Aux battery via a 10A in-line fuse. Connect the ground terminal to the chassis. When you push the button you will here the solenoid click in, thus putting both batteries in parallel.

PS: I agree the Web drawing is unclear. Do not wire the blue wire to ground!!!!!!

Sparky

Blue,
You probably already have your answer but just to reinforce what has already been said, this is how I have it set up, (with directions form REDARC)

1/ The blue wire goes to a pin at the back of a momentary on switch which is spring loaded and fitted to the dash.

2/ The second pin on the back of the switch is wired back to the thread on the top of the isolator to which the starting battery is wired.

So, cable from starting battery to isolator, put wire on this thread, run to switch, then from switch back to blue wire on Isolator. When switch pressed this joins both batteries together and, hey presto.

As a hint, strip the wire and crimp in place to the blue wire, I tired to get the blade lug out and broke it.

Hope this helps

Rolande