Redarc SBI12 continually switching

[Bazza Senior Member Find all posts View Profile Close Bazza]

Just got back from 5 days a Coffs Harbor. Had a great time. On the way there and back, at every set of red lights, and at any time the motor was idling, all I could hear was that bloody isolator clicking in and out every 5 seconds or so. The only way I could stop it happening or make it less frequent was to run with the headlights on. I could also get it to operate simply by pressing the brake on and off. I figure that the battery voltage must be sitting on the units switching voltage.

As an anal retentive, I hate noises and rattles of any kind.

I'm that close to ripping it out and putting in a simple manually operated switch and solenoid. I have checked all connections including the earth, cables are sized right, and both batteries are near new. The Redarc is also mounted close to the starting battery. Everything seems good?

I left an question on the Redarc site and one of their techs got back to me. He was trying to be helpful and told me to check all the things I'd already done. After that he just keep pushing their DC-DC charger as a remedy.

I don't see the need for a DC-DC charger and would prefer to stay with an auto or manual isolator.

Has anyone else had this issue and resolved it?

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Not me but 2 mates, one in a Pajero and one in a Patrol. In both cases it was a bad earth in the system, take all the cables off and give them a good cleanup.

Cheers Andrew

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Has worked ok but just gone faulty?

What model car to you have?

Do you run a booster diode?

Assuming it has just gone faulty, have you installed any new electrical load into the car?

The VSR is voltage sensitive, it is disengaging as the voltage of the alternator will be lower at idle, hot weather or an added load would cause it to drop.

If this has just developed I would be checking your alternators output voltage and see what it is and compare this to the cut in cut out voltage of the Redarc in its specs.

A booster diode if suitable for use with your model would prevent this and speed up recharge times but if you haven't needed one todate then you probably don't need one.

Cheers
Leigh

[Bazza Senior Member Find all posts View Profile Close Bazza]

Hi Leigh,

It's been fitted to my 2009 V6 for about 6 months now and has only recently started doing this. I do have one of your diodes fitted. Output voltages seem OK, about 14.3v cold start,dropping back slightly when warmed up. I've also noticed it switching on & off in the afternoons after driving home from work ( about 65klms ). If I switch the highbeam on for about 30 seconds it settles down. I have not added any extra electrical load. I have reconfigured most of my accessories ( fridge, lightbar, driving lights, horns, accessory outlets etc ) to the second battery via a fuse box.

The only thing I haven't tried is taking the isolator's earth connection directly to the start battery. It is currently connected to an existing central earth connection on the inner guard. Strange thing is that it doesn't do it all the time, but is becoming much more frequent.

Bazza

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Turning on the lights will lower the voltage a little, so it may be turning off
due to high voltage or low voltage.

What voltage does it play up at?

[Bazza Senior Member Find all posts View Profile Close Bazza]

Turning on the lights will lower the voltage a little, so it may be turning off
due to high voltage or low voltage.

What voltage does it play up at?

Hi Leigh,

I think it's at about 13.2volts but I will need to check. I'm off work for the rest of the week so I will take some accurate readings and get back to you.

Thanks for your interest.
Bazza

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

No problem, it should drop out till the voltage drops below 12.7V if it drops out before
that it is a dud.

Cheers
Leigh

[Bazza Senior Member Find all posts View Profile Close Bazza]

Leigh,

I took some readings while the vehicle was stationary. Did not witness it switching on & off. Bugger! I will keep a multimeter in the Prado and stop and take readings when it starts doing it again.

Cold start voltage on start battery : 14.5v ( solenoid connected - LED on )

Vehicle at normal run temperature ( after 15-20 minutes idling ) : 14.0v

Engine off - Solenoid disconnected at 12.6v ( LED off )

Cold standing voltage on both batteries ( isolated ) 12.8 - 12.9volts

Bazza

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Yep, sounds like a plan, maybe a heat related fault that will only be apparanent
when driving, voltages look ok.

Cheers
Leigh