Having problems getting 12v power in the caravan via pin 2 using a 7 pin socket.
Mutley said
04:43 PM Mar 12, 2016
Hi all,
Sorry if this has been covered before!
I'm have an issue getting power back to the 3 way fridge in the caravan, from the 7 pin socket on the Pajero. When we had the brake controller installed (Tekonsha Primus IQ), the installer ran a "hot wire" back from the cranking battery under the bonnet, to pin 2 in the 7 pin plug at the rear, via an auto re-set circuit breaker near the battery (it was installed before we bought the van). However, when I connect the van to the car & start the car, the 12v in the van continually cuts in/out at 2/3 second intervals (the 12v radio in the van is continually starting/stopping)
We have an Anderson on the bumper of the Navara & there is an Anderson connected to the battery box on the van via very heavy wiring. No issues when I run it this way (even without a battery in the box). Everything on 12v in the van runs fine.
The electric brakes are running fine too.
Could the issue be earthing? The earth wire coming into the battery box from the Anderson on the Navara is earthed in the battery box. Everything in the van seems to be earthed to the chassis, as it all works fine using that method. The only return earth to the 7 pin plug is from the van is electric brakes & is in pin 3.
Or could it be a faulty circuit breaker?
Any help genuinely appreciated :D
woofta and precious said
05:18 PM Mar 12, 2016
Hi Mutley,
The problem could also be in the circuit breaker, especially being of the auto reset kind?
Try bypassing it (maybe with a fused wire just in case)
It would help if we had the type of plug on the back of the van and whether or not you have a breakaway device fitted.
Baz421 said
09:12 PM Mar 12, 2016
Sounds like the relay is either doing its job ie circuit overload OR it's faulty.
I would also check the 7 pin plug as they sometimes don't like 15-20 amps current and start to melt especially if wiring is a bit sus (too small) or poor connections.
When someone asked for size of relay they meant the current rating in amps Mutley.
PeterD said
12:11 AM Mar 13, 2016
Mutley, the wire in your photo looks a little on the light side.
You did not specify which 7 pin plug you are using. If it is the flat style of connector then the pins art to light to carry the current that the fridge will draw. You need to replace it with the flat 12 pin connector and run the fridge through pin 9 and earth through pin 10.
Mutley said
01:15 AM Mar 13, 2016
Baz421 wrote:
Sounds like the relay is either doing its job ie circuit overload OR it's faulty.
I would also check the 7 pin plug as they sometimes don't like 15-20 amps current and start to melt especially if wiring is a bit sus (too small) or poor connections.
When someone asked for size of relay they meant the current rating in amps Mutley.
G'day Baz,
Thanks for your reply! :)
The circuit breaker doesn't have amps stamped on it. How do I know if the circuit is overloaded mate? The plug is fine, no melting, I've been pulling it apart & putting it back together all day. Getting to the stage of running some heavy cabling from the battery to an Anderson on the rear bumber & saying bye bye to the hot wire lol! :(
Mutley said
01:25 AM Mar 13, 2016
PeterD wrote:
Mutley, the wire in your photo looks a little on the light side.
You did not specify which 7 pin plug you are using. If it is the flat style of connector then the pins art to light to carry the current that the fridge will draw. You need to replace it with the flat 12 pin connector and run the fridge through pin 9 and earth through pin 10.
Thanks Peter, Its a 7 pin round plug. I've just about had enough of it & am thinking of running fused cabling back from the battery to an Anderson on the rear bumper like I have on the Navara. I wish the guy who fitted the brake controller on the Pajero had never bothered running the hot wire through pin 2! I never asked him to do it, he just did. He has the earth cable running from the battery back to pin 5 & the live wire back through pin 2. The electric brakes work fine, so I'm guessing he's run them off the brake lights, but the 12v in the van operates like its running off an indicator wire.
Baz421 said
04:17 PM Mar 13, 2016
Mutley wrote:
Baz421 wrote:
Sounds like the relay is either doing its job ie circuit overload OR it's faulty.
I would also check the 7 pin plug as they sometimes don't like 15-20 amps current and start to melt especially if wiring is a bit sus (too small) or poor connections.
When someone asked for size of relay they meant the current rating in amps Mutley.
G'day Baz,
Thanks for your reply! :)
The circuit breaker doesn't have amps stamped on it. How do I know if the circuit is overloaded mate? The plug is fine, no melting, I've been pulling it apart & putting it back together all day. Getting to the stage of running some heavy cabling from the battery to an Anderson on the rear bumber & saying bye bye to the hot wire lol! :(
Is the wire to the van getting hot??? If so then the current is too great for the wire size and creates resistance.
Yeh I know many circuit breakers have no markings.
Mutley said
09:33 PM Mar 13, 2016
Baz421 wrote:
Mutley wrote:
Baz421 wrote:
Sounds like the relay is either doing its job ie circuit overload OR it's faulty.
I would also check the 7 pin plug as they sometimes don't like 15-20 amps current and start to melt especially if wiring is a bit sus (too small) or poor connections.
When someone asked for size of relay they meant the current rating in amps Mutley.
G'day Baz,
Thanks for your reply! :)
The circuit breaker doesn't have amps stamped on it. How do I know if the circuit is overloaded mate? The plug is fine, no melting, I've been pulling it apart & putting it back together all day. Getting to the stage of running some heavy cabling from the battery to an Anderson on the rear bumber & saying bye bye to the hot wire lol! :(
Is the wire to the van getting hot??? If so then the current is too great for the wire size and creates resistance.
Yeh I know many circuit breakers have no markings.
Hi again Baz, my apologies for my slow reply; I've been out working on it all arvo!
The wire to the van was stone cold Baz - I've had enough of it & run cabling to an Anderson to the rear of the car & connected that through the Anderson coming from the battery box on the van - Fixed!
:D
Baz421 said
02:47 PM Mar 14, 2016
Good result and probably a lot safer too although 12V is pretty safe.
The best thing is YOU know what you have done rather than someone else's attempts eh! The good ol Aussie way.
Well done.
Hylife said
02:49 PM Mar 14, 2016
Never expect a good 12V supply from a trailer plug. Their wires are just too small to carry anything but the lightest of loads. Fine for exterior lights and electric brakes but useless for anything else. +1 to using an Anderson Plug every time.
Hi all,
Sorry if this has been covered before!
I'm have an issue getting power back to the 3 way fridge in the caravan, from the 7 pin socket on the Pajero. When we had the brake controller installed (Tekonsha Primus IQ), the installer ran a "hot wire" back from the cranking battery under the bonnet, to pin 2 in the 7 pin plug at the rear, via an auto re-set circuit breaker near the battery (it was installed before we bought the van). However, when I connect the van to the car & start the car, the 12v in the van continually cuts in/out at 2/3 second intervals (the 12v radio in the van is continually starting/stopping)
We have an Anderson on the bumper of the Navara & there is an Anderson connected to the battery box on the van via very heavy wiring. No issues when I run it this way (even without a battery in the box). Everything on 12v in the van runs fine.
The electric brakes are running fine too.
Could the issue be earthing? The earth wire coming into the battery box from the Anderson on the Navara is earthed in the battery box. Everything in the van seems to be earthed to the chassis, as it all works fine using that method. The only return earth to the 7 pin plug is from the van is electric brakes & is in pin 3.
Or could it be a faulty circuit breaker?
Any help genuinely appreciated :D
Hi Mutley,
The problem could also be in the circuit breaker, especially being of the auto reset kind?
Try bypassing it (maybe with a fused wire just in case)
Pic of 7 pin round plug wiring inc
Thanks W & P, I've been thinking the same thing. I have a spare in line fuse holder in the shed, I might give that a try tomorrow!
Thanks again! :)
Sounds like the relay is either doing its job ie circuit overload OR it's faulty.
I would also check the 7 pin plug as they sometimes don't like 15-20 amps current and start to melt especially if wiring is a bit sus (too small) or poor connections.
When someone asked for size of relay they meant the current rating in amps Mutley.
You did not specify which 7 pin plug you are using. If it is the flat style of connector then the pins art to light to carry the current that the fridge will draw. You need to replace it with the flat 12 pin connector and run the fridge through pin 9 and earth through pin 10.
G'day Baz,
Thanks for your reply! :)
The circuit breaker doesn't have amps stamped on it. How do I know if the circuit is overloaded mate? The plug is fine, no melting, I've been pulling it apart & putting it back together all day. Getting to the stage of running some heavy cabling from the battery to an Anderson on the rear bumber & saying bye bye to the hot wire lol! :(
Thanks Peter, Its a 7 pin round plug. I've just about had enough of it & am thinking of running fused cabling back from the battery to an Anderson on the rear bumper like I have on the Navara. I wish the guy who fitted the brake controller on the Pajero had never bothered running the hot wire through pin 2! I never asked him to do it, he just did. He has the earth cable running from the battery back to pin 5 & the live wire back through pin 2. The electric brakes work fine, so I'm guessing he's run them off the brake lights, but the 12v in the van operates like its running off an indicator wire.
Is the wire to the van getting hot??? If so then the current is too great for the wire size and creates resistance.
Yeh I know many circuit breakers have no markings.
Hi again Baz, my apologies for my slow reply; I've been out working on it all arvo!
The wire to the van was stone cold Baz - I've had enough of it & run cabling to an Anderson to the rear of the car & connected that through the Anderson coming from the battery box on the van - Fixed!
:D
Good result and probably a lot safer too although 12V is pretty safe.
The best thing is YOU know what you have done rather than someone else's attempts eh! The good ol Aussie way.
Well done.
Never expect a good 12V supply from a trailer plug. Their wires are just too small to carry anything but the lightest of loads. Fine for exterior lights and electric brakes but useless for anything else.
+1 to using an Anderson Plug every time.