split charge relay melted help please

[djhammy]

HI guys i've had a problem with fuses sporadically going on my cheapo hella split charge relay from JK. It had been fine with a 20amp one in place for a while though i realise that the unit isn't really very good and i was about to buy a heavy duty one. The wiring is heavy duty except the supply from the to the replay fitted by a garage I was also going to replace that as well.

The Relay has a wire in from the engine, an earth lead, one going to the leisure battery and one to the main battery.

I noticed this afternoon that the fuse had melted a tad so replaced it. By the time i got home that had melted or more desoved and so had part of the split charge replay unit.

Any way I have decided to take the relay out for the moment until i get a better one and just join the supply wire to the one to the main battery so that keeps charging.

All easy enough i thought until i traced the supply to the coil. I thought it would be attached to the alternator so i'm getting very confused here.

Can any one tell me if this is how it works as I'm baffled.

Cheers
Dave

[kevtherev]

you need at least a 50 amp relay.. 70 amp is ideal

the trigger wire to the coil is to close the relay or "switch it on"

[djhammy]

Or does the charge go to the main battery from the alternator then travels up to the split charge relay that way and the wire going to the coil is just a power supply for the relay unit to function?

I plead total ignorance m'lord.

Dave

[VWCamperfan]

Yep, your last post is how it should be. From alternator to starting battery, then on to split charge relay and from the relay to the leisure battery.
The other cable to the coil is as Kev said, it switches the relay to the closed position when ignition is on and connects the two batteries.
Again, wiring and relay should be able to handle at least 30 amps, 50 is better and any higher a bonus! Just remember to stick a fuse in that has a lower rating than the weakest point in the split charge system. That could be the amp rating of the cable, the connectors or the relay. That way the fuse will blow first before anything else!

[djhammy]

Thanks guys appreciate your help. I learn something new every day for sure.

I did wonder why my main battery never went flat when the fuse melted on the relay. Still it's worrying it melts so easily. I hardly use the leasure battery either.

My engine is running fast at present due to carb problems (about to be fixed tomorrow) would that send a larger charge down the line? i had a new voltage regulator fitted at Xmas so i don't think it should?

Dave

[bigherb]

If the wire went to the coil then it was fitted incorrectly causing both batteries to be connected together when you are cranking the engine. If the starter battery was a bit low the relay would have been carrying a high load from the leisure battery to help start the engine.

[djhammy]

HI yes the electric feed to the relay was fitted to the coil. The garage fitted it. So do i need to find an alternative live feed for the relay when i get a new one? Thanks for the info.

Cheers

Dave

[VWCamperfan]

Yeah, that would be a good idea. Instead of running from the coil, run the cable from the alternators charging light wire (thin blue cable from alternator to connector behind dash). This will ensure the relay only closes when the alternator is charging, after the engine has started.

[djhammy]

Can any one recommend a decent relay to replace my melted hella one?

Thanks.

[kevtherev]

plenty to choose from.. Maplins, Halfords, etc

here's the maplin one http://www.maplin.co.uk/Module.aspx?Mod ... &U=strat15" onclick="window.open(this.href);return false;