Electrical Wiring up hot wires

[Four of us]

I'm after some advice about wiring up a hotwire. I have been told by the auto sparky I can get away with wiring up a 6 b@s cable directly from the tug battery to the 12 pin plug via a fuse which will be the cheapest about $100. The most I will be traveling for will be about 11 hrs before I plug into 240v. I was told that if I didn't disconnect the van when I stopped for a long period of time I could drain the tug battery without an isolator.

Would this be ok to do as I will only be doing fairly short trips? Any advice would be great...Thanks

 

[peterg]

Fine if all you do is travel and disconnect, no stops, no loos, no lunch, etc. My old tug was wired that way but every time I stopped for more than 1/2 hr the battery drained if I had the fridge on in the van. An isolator is the only way to go.

 

[dagree]

This has been discussed recently @Four of us .... Fridge Switch Method. For example.

There are different options around for example:

1. Rely on the brain to unplug the hotwire.
2. Use a relay powered from an ignition source
3. Fit a motion sensing switch
4. Fit a Low Voltage Cutout Device

 

[chartrock]

G'day Chris, the length of your trip will really have no bearing on your situation, it will depend purely on the duration of your stops. I found a $8 relay in the ignition circuit the answer as it allows current when running but as soon as you stop, no current and your main battery is protected.

 

[Four of us]

G'day Chris, the length of your trip will really have no bearing on your situation, it will depend purely on the duration of your stops. I found a $8 relay in the ignition circuit the answer as it allows current when running but as soon as you stop, no current and your main battery is protected.

Thanks Paul, I was just getting confuse by the different advice I was getting from different sparkies. I'm taking the new car to bathurst in October with the van. So I think I will tell the sparkie to put a relay in for me...like you and others have said no power to car = no power to van. It shouldn't cost that much extra to throw a relay in for me.

 

[Crusty181]

@Four of us $100 sounds a little on the cheap side. Twin core 6b&s cable is worth up around $10/metre, ie$50 worth of cable, and I dont know too many Auto Elec's that would run it and fit if off for $50.

Just be mindful to be effective it should be twin core with negative back to the battery and not earthed off on the chassis. I had 2 Auto Elecs try to sell me 6mm cable when I first went shopping for 6b&s. The parts for the relay are pocket change .. hopefully he uses the same labour rate

The smaller fridge draws around 14amps from memory ... so its probably drawing similar to your cars headlights on high beam. If you had a good battery youd get away with it, but in comparison most people wouldn't take the risk by knowingly leaving the headlights on high beam for a hour whilst they sat in cafe having lunch. Its quiet a heavy drain on the battery.

I have the ignition relay, and if we stop for an extended time, or its a warm day Ill flick the gas on whilst I stopped.

 

[Four of us]

I should clarifying I'm getting a tow pro installed at the same time as the hot wire that's why the auto elec is charging $100 extra for the hot wire. But he did say that was only hooked up to the battery not a relay. But I'm going to get it connected to a relay.

 

[Crusty181]

I should clarifying I'm getting a tow pro installed at the same time as the hot wire that's why the auto elec is charging $100 extra for the hot wire. But he did say that was only hooked up to the battery not a relay. But I'm going to get it connected to a relay.

Good choice. Easiest fool proof solution

 

[Roadkill]

I have found one of the sidewinder battery isolator products works well. A little more expensive than just a relay, but once connected, looks after things itself.

Cheers.