Relay question

[Jaybird]

I will be picking up my new Discovery hopefully next week, I beleive it came of the line on Tuesday 24th.
It has the fridge connection coming to an anderson plug connection on the drawbar which connects to same on the rear of tug. I had the tug anderson originally wired to suit an electric boat winch and it is wired from the battery through a 50amp relay, its wire size to rear of vehicle is very heavy. The fridge in the van is the 90ltr 3 way.
The plug on the car is live even with the ignition off.
I dont understand what a relay does but looking on google it appears to be a switch so should it still be live when the car ignition is off or is it faulty.

Thanks

Terry

 

[seanparky]

Jaybird. Congrats on new van. A relay is an electrical switch. Is your anderson plug live with ign turned off or is your trailer plug live. Depending on how the van is wired up has been awhile since i have worked on the jayco but when i get my own dont worry it will get a full electrical inspection and work over. This mite help.

Trailer plug info..Pin numbers and wire colours.
Pin 1- Yellow- Left indicator
Pin 2- Black- Reverse light or aux power
Pin 3- White- Earth
Pin 4- Green- Right indicator
Pin 5- Blue- Electric Brakes
pin 6- Red- Brake light
Pin 7- Brown- Tail lights

What you want is the anderson plug to come live when the ign switch is turned on so your fridge is then running only when the vehicle is running. A test light will help you work this out. Did you get a diagram of the electrical circuit when the van was purchased?

Hope this helps in some way.

 

[Jaybird]

Jaybird. Congrats on new van. A relay is an electrical switch. Is your anderson plug live with ign turned off or is your trailer plug live. Depending on how the van is wired up has been awhile since i have worked on the jayco but when i get my own dont worry it will get a full electrical inspection and work over. This mite help.

Trailer plug info..Pin numbers and wire colours.
Pin 1- Yellow- Left indicator
Pin 2- Black- Reverse light or aux power
Pin 3- White- Earth
Pin 4- Green- Right indicator
Pin 5- Blue- Electric Brakes
pin 6- Red- Brake light
Pin 7- Brown- Tail lights

What you want is the anderson plug to come live when the ign switch is turned on so your fridge is then running only when the vehicle is running. A test light will help you work this out. Did you get a diagram of the electrical circuit when the van was purchased?

Hope this helps in some way.

Thanks for your reply
The anderson on the car is live all the time regardless of ignition. ( its wired direct to the battery) maybe I will need a fridge switch
There is also a live connection to the 7 pin plug. not sure why but the auto elec said I might need it sometime so put it in.
The van fridge is going to be wired to the anderson plug.
I havent got a wiring diagram as yet for the van

 

[macca]

I remember this link. I think Jayco change a few wires that others dont.
http://www.expandasdownunder.com/sh...er-12-Volt-Fridge-Hotwire-12-Volt-Hotwire-DIY

Geoff

 

[seanparky]

From memory the live wire on the 7pin plug will be for lights on the van. But if you already have batts in van you dont need that option. Ideally you want van and car isolated when car turned off. Have the anderson plug put thru solenoid. There are plenty on the market. Wiring can get tricky as there are so many ways of doing things. Now if this was my van. Id have the fridge wired to the batts in van wired thru a relay so only came on when driving. The charging circuit to van batts from anderson plug.

 

[Jaybird]

Thanks Sean

The van has a 100amp/hr battery and 120w solar panel.
I will take your advise and get a solenoid put on the anderson plug.
I still would like to know what the 50amp relay does that is on the anderson wiring.

Thanks
Terry

 

[seanparky]

Ok there should be 4 terminals or if the heavy duty relay two pins and two studs. A test light will help with the checking of the relay. On a regular relay there are numbers under them. Pin 85 0r 86 are the coil pins. One of these should be connect to earth and the other to ign or accessories. Check that the relay is not on with the key in the acc position. The other two pins are 30 and 87. These are the contact terminals. Pin 30 should be connected to the batt thru a protection device ( preferably a circuit breaker) Pin 87 should be goin to the anderson plug. Ok if you have no power going to 85 or 86 but power going to the anderson plug the relay is faulty and the contacts have welded shut. Replace.

 

[Jaybird]

Thanks for that Sean,
I'll check it tomorrow

 

[Ch00ka77]

I would also check out the red arc web site as we have a hundred amp solenoid/isolator which is power all the time from the anderson plug but turns off when the start battery or secondary battery drops to 10.4 volts ther are also plenty on eBay to buy as well. I have had one on for several years now and it has not lets us down yet and all my mates have them on there's as well.

 

[bully66672]

I've got the Red arc isolator fitted to my Landcruiser between the battery and the Anderson plug.
Works great, never had a flat battery in the car.

Cheers

 

[millers]

Jaybird,

Another thing to consider is that what you are calling a relay may be a circuit breaker. That is an automatic fuse that will reset itself. So if it only has 2 terminals then it is a circuit breaker and therefore will be on all of the time. If it has 4 terminals then it will be a relay and should be switched (as described by seanparky). It would be best to check the relay by disconnecting the coil and this should stop power to the anderson plug. If power is still available at the anderson plug after diconnecting then the replay is faulty. Be careful when disconnecting any electrical stuff so that there are no positive (active) wires loose and could short out and blow fuses.

Cheers

 

[Jaybird]

Thanks to you all I certainly have a lot of info to work with and will have a good look at all on Wednesday on my day off

Terry

 

[Tuco]

I would also check out the red arc web site as we have a hundred amp solenoid/isolator which is power all the time from the anderson plug but turns off when the start battery or secondary battery drops to 10.4 volts....

Gee Chooka - I'd be very suprised if your Prado would turn over if the "Start" battery was down to 10.4 V !!

I've got a Redarc SBI12 in my Patrol and the "Start" is isolated once the pair drop below 12.7V.

With 120W of solar on top of the 'van and another 120W solar on the top of the Patrol, we don't ever have low battery problems. We have an ARB 35L fridge (usually run as a freezer) in the Patrol and a Waeco 110L 12V in the 'van.

 

[ElectricGuru]

Hey Jaybird

Best thing to do is if you are unsure, post some photos of the setup so we can have a look.

Also, I have the Redarc isolator as well that cuts the supply to the anderson plug if the voltage drops below 12.8 Vdc so the anderson is usually on.

Cheers.

 

[Jaybird]

I have established that it appears to be a circuit breaker and not a relay. It is the double units on the left of the photo the other on the left is for the brakes.
They were originally for a boat winch and were 50amp. So apart from the fact that it is always live is it OK to run the fridge while driving, I will have to sort out the switching problem after I pick up the van which Thursday 9th Aug

 

[Ch00ka77]

Gee Chooka - I'd be very suprised if your Prado would turn over if the "Start" battery was down to 10.4 V !!

I've got a Redarc SBI12 in my Patrol and the "Start" is isolated once the pair drop below 12.7V.

With 120W of solar on top of the 'van and another 120W solar on the top of the Patrol, we don't ever have low battery problems. We have an ARB 35L fridge (usually run as a freezer) in the Patrol and a Waeco 110L 12V in the 'van.

Yeh sorry my apologies a bit of a mental blank there after a couple of froffys on Sunday night....

 

[millers]

I have established that it appears to be a circuit breaker and not a relay. It is the double units on the left of the photo the other on the left is for the brakes.
They were originally for a boat winch and were 50amp. So apart from the fact that it is always live is it OK to run the fridge while driving, I will have to sort out the switching problem after I pick up the van which Thursday 9th Aug

If you need to run the fridge to bring the van home then yes it is ok. If you do not need the fridge then you can turn it off at the fridge. I do not believe that the fridge will get very cold if started on 12V (better to use 240V or gas), 12v is more for traveling and keeping cold rather than getting cold.

Just be aware that if you run it on 12V you have a big drain on your battery when you turn the engine off. So if you stop for awhile with the fridge on, disconnect the anderson plug and then re-connect prior to continuing on.

Cheers