Rotronics MH-10 Possible fault

Submitted: Sunday, Jul 30, 2006 at 20:56

ThreadID: 36293 Views:10175 Replies:5 FollowUps:4

This Thread has been Archived

Hux1405

Hi guys,

This is my first post, I have a Landrover Discovery 300TDi, I aslo have the dual batteries installed. Using the Rotronics Isolator/Charger, the aux battery seems to drain really quickly, although when the vehicle is started it takes about 1min and the the alternator seems to send charge through.

I am lead to believe that if the aux battery was installed it would deliver charge through to all devices installed on that circuit, so long as the battery was charged, then when the battery dropped below a certain voltage, it open the charge circuit.

Is there any ideas that could possible help, if not, possibly some small test that I could perform?

Thanks for your time.

Dave

Back Expand Un-Read 0 Moderator Share

Reply By: Member - Tony T (VIC) - Sunday, Jul 30, 2006 at 21:13

Sunday, Jul 30, 2006 at 21:13

Straight back to the guys who installed the system, I'd reckon, if you have that info. But there's some great sparkys on this site who might help you- only wish i had a clue about electrics-

AnswerID: 186149

Follow Up By: Hux1405 - Sunday, Jul 30, 2006 at 21:24

Sunday, Jul 30, 2006 at 21:24

Thanks for your reply.

Cheers,
Dave

FollowupID: 443169

Reply By: Brett_B - Sunday, Jul 30, 2006 at 21:19

Sunday, Jul 30, 2006 at 21:19

Hi Dave

I have a MH 10 fitted in a new Hilux, both batteries, main and Aux are new, it can take up to 1 min before the Aux battery will start to receive a charge (green light on)

Sounds like the MH10 "could" be working ok, I would go to basics and check the batteries, have you done this ?

I do have a full MH10 installation/data/instruction manual in pdf form, if you want it shoot me your email and I will send it through, the manual may help you fault find ??

AnswerID: 186156

Follow Up By: Hux1405 - Sunday, Jul 30, 2006 at 21:23

Sunday, Jul 30, 2006 at 21:23

Thanks for replies, this site is fantastic.

I would love the manual in PDF.

dhuxta@tpg.com.au

Cheers,

Dave

FollowupID: 443168

Follow Up By: Brett_B - Sunday, Jul 30, 2006 at 21:50

Sunday, Jul 30, 2006 at 21:50

Its on its way.

FollowupID: 443178

Reply By: SteveL - Sunday, Jul 30, 2006 at 21:50

Sunday, Jul 30, 2006 at 21:50

I had a MH-10 which failed after only 3 years and have a friend who had one which also failed after a similar period of time.When I took it to an auto elec. he told me of others he had come across.I chose to go with something more basic
instead of a box full of electronic components which is not particularly dirt or waterproof.

Member
My Profile My Position Send Message

AnswerID: 186168

Reply By: Member - Phil G (SA) - Monday, Jul 31, 2006 at 14:58

Monday, Jul 31, 2006 at 14:58

Often this is due to incorrect installation.

There are a few small wires coming out of the MH10. The black one is the earth wire - make sure its earthed! Then there is a voltage sensing wire that must be connected to the terminal that goes to starting battery. Put this wire on the wrong terminal and it will prevent the isolator from working. Thirdly, theres another wire that needs to be hooked up to a source of IGN power, so the unit only consumes power when the vehicle is running - most installers will use the wiper motor wiring for this.

To test it all, hook a voltmeter (or DMM) up to the 2nd battery. Start the vehicle - this initially will have no effect on the 2nd battery voltage. Then after a short time - usually up to a minute, the LED will light up, and the second battery voltage will rise to 13.5 - 14.4 volts.

Need to also check that there are no accessories draining your second battery. Also need to be sure that your second battery has 2 robust earth leads - one going to the motor and one going to the body, as per Rotronics instructions.

Cheers
phil

AnswerID: 186272

Follow Up By: Member - Phil G (SA) - Monday, Jul 31, 2006 at 15:18

Monday, Jul 31, 2006 at 15:18

Just to ad the following info from teh Rotronics website:
Also I noted these units have a 3 year warranty.

Wiring Diagram:

And the following info:
MH10 Operation :
The Main battery is recharged by the alternator when the engine is started. The alternator voltage is monitored by the MH10 and when the Main battery is "On Charge", the Vehicle Auxiliary battery is connected by the MH10 for recharge. The Green Led will light on the unit and the BCM monitor [ if fitted ], when the Vehicle Auxiliary battery is connected for charging. The Vehicle Auxiliary battery will be isolated from the Main battery if the alternator overloads, to prevent the Main battery discharging into the vehicle auxiliary battery. The Main battery and the Vehicle Auxiliary battery, are Isolated when the engine is "Off".

FollowupID: 443317