Thread: Redarc issue

It depends on which battery your lights are wired into. If they are still standard, then they will be wired off the main battery, in which case the redarc won't save you. If you have got the lights wired to the auxillary battery, then check to see if the little LED on the redarc stays on after you switch the engine off. It usually only takes a few seconds for the redarc to open and the LED to go off. If it stays on for quite a while, you may have an issue.

Cheers - Gav.

Wot Gav said. In the situation you were in a jump start from the spare battery would have worked.

cheers, DL

The other thing you can do on the redarc, is attach a bypass so you can activate it if needed by a switch. There should be a spare wire hanging off the relay - if you apply power to this, the relay will click in, and reconnect the two batteries. A word of caution here - depending on the model you have, it may be an 80 or a 120 amp unit, so using it to start the vehicle from the auxillary battery could do it a mischief. What 350RRC said about jumping it from the other battery is a better idea.

Cheers - Gav.

Hmmm... for now I can do the jumpstart method, but maybe I should get the headlights rewired to the auxiliary.

Originally Posted by Ranga

Hmmm... for now I can do the jumpstart method, but maybe I should get the headlights rewired to the auxiliary.

Suggestion: if the existing solenoid isn't strong enough, have another solenoid linking the batteries, activate it with a button getting power from the reserve battery. This way your jump starting is immediate and fuss free. That's how mine is set up.

Originally Posted by Ranga

Hmmm... for now I can do the jumpstart method, but maybe I should get the headlights rewired to the auxiliary.

Yep, good idea - All my lights, interior lights, CD player and lighter are now run off the auxillary for that very reason. Bee Utey's idea about the extra solenoid is a good one too - see how you go.

Cheers - Gav.

Originally Posted by bacicat2000

check to see if the little LED on the redarc stays on after you switch the engine off. It usually only takes a few seconds for the redarc to open and the LED to go off. If it stays on for quite a while, you may have an issue.

Cheers - Gav.

If the main battery is "fully charged" the redarc LED may stay on for quite a while after turning off the engine. (mine often stays on overnight) The LED goes off (relay opens) when I next start the car or switch on something powered by the main battery ie when its voltage drops slightly.

Originally Posted by bacicat2000

Yep, good idea - All my lights, interior lights, CD player and lighter are now run off the auxillary for that very reason. Bee Utey's idea about the extra solenoid is a good one too - see how you go.

Cheers - Gav.

Hi,
a brief tale of woe on this subject.

In the beginning:
New Toyota Dyna set up as a camper van, 2 batteries separated by what was essentially 2 diodes with the Alternator going to the join between the diodes. i.e. Batteries could not 'see' each other, and could only be 'seen' by the alternator. Each battery charged independently of the state of the other battery. (well that was the theory anyway)
Headlights were removed from the cranking battery loom and spliced into the house battery.
This worked well for about 14 years till one teenage son put the house battery in reverse polarity. This shorted back through the alternator and cooked the diodes in that and the battery isolator. (note to self: never run unfused wires)
Drove vehicle to auto electrician who reset the wiring from the alternator back to where it should be and supplied a new alternator.
The vehicle was now back to standard except for the headlights still on the house battery.
New Battery Isolator:
I was persuaded that a new Rotronics isolator which isolated the house battery when the cranking battery dropped from full voltage would be much better than the diode separation that I had previously. This seemed to work ok for a while until the batteries were getting a bit old, and I tried to drive at night.
The vehicle started ok, and I turned on the headlights - remember these were on the domestic battery which didn't get charged till the cranking battery reached full charge.
The lights were a pathetic dull glow, and the alternator was busy charging the cranking battery - not the house battery.
Not to worry, just wait a while till the cranking battery charged up.
As soon as the cranking battery was sensed as being charged, the house battery and the headlights were connected - momentarily, and then disconnected again - until there was enough charge in the cranking battery and then ............ You get the picture? Yep the lights would come up and down in cycles of about 5 seconds on, and 60 seconds off - not real good for night driving.
OK I did have 2 batteries that were on their last legs, but changing the head lights back to the cranking battery circuit solved the cycling problem.
The Alternator seemed able to keep the charge up to the cranking battery and headlights and charge an unladen house battery with out any problems right from the moment of vehicle start up.

Just a cautionary tale of woe of a problem that you may have connecting headlights to a secondary battery.

cheers