found a relay

[henry martin]

In ther engine compartment alongside the battery,
its an aftermarket device,
live wire shows up with an in-line fuse
(when the engines running only)

its a 10A Blown fuse with a heavy gauge 25A wire leading off,
apparently towards the leisure battery area.

Might I be right in thinking its a charging circuit
and how do I test it for current,

or is 12V proof enough?

Thanks HM

[dbroada]

my guess is that it is your split charge relay. 10A is very low for that so I'm not surprised it has blown. You can get a large current flow if the LB & main battery are at very different charge states when the relay operates.

Do both batteries show the alternator voltage when the engine is running? If they do then that relay is probably NOT your split charge relay. If the LB doesn't show the alternator voltage replace the fuse (after recharging your LB on the bench if necessary) and check again.

[henry martin]

my guess is that it is your split charge relay. 10A is very low for that so I'm not surprised it has blown. You can get a large current flow if the LB & main battery are at very different charge states when the relay operates.

Do both batteries show the alternator voltage when the engine is running? If they do then that relay is probably NOT your split charge relay. If the LB doesn't show the alternator voltage replace the fuse (after recharging your LB on the bench if necessary) and check again.

Sorry, er you've lost me a bit.
Would you mind going over it again please.

I traced the Wire forwards from relay, and found it
appeared through a hole in base of floorpan below passenger seat, from there it went simply below rubber mat into drivres side LB compartment which is where, when I gently pulled it,

there was a spark and the relay fuse must have blown.

Replace fuse and checked for Volts;

engine off =Nil
engine running= 12V

I've now connected this single lead to the positive connection on the LB Together with Blower/light/tap wiring

Not quite sure how to test for alternator voltage with batterys connected

or have I got wrong end of stick?


cheers in advance HM

[dbroada]

the most common set up on a small van is a split charge relay like the above drawing. The 2 batteries are joined through the relay contacts. The relay is fed from the "alternator working" signal and this means the batteries are only joined when the alternator is working.

If you check the battery voltages with the engine off they may be different from each other but should both be above 12v, preferably about 13v. Start the engine and they should both jump to the voltage that the alternator is producing, about 14v. If the LB doesn't show this increased voltage the relay isn't working.

[henry martin]

I was studying this same drawing all week
as a matter of fact with some trepidation

it was only this morning poised over the engine
I noticed the relay again.
When I first bought the van I checked for voltage
with Key in but not engine running
and of course saw nothing
I know now the alternator is responsible for powering this circuit.

cheers I'll check volts Tomorrow

[irishkeet]

[R0B]

henry.do you really think you should be messing with your vans electrics.

Sorry, er you've lost me a bit.

Not quite sure how to test for alternator voltage with batterys connected