Electrical Gremlins Help Needed

Submitted: Wednesday, Jul 11, 2012 at 21:25
ThreadID: 96815 Views:2948 Replies:6 FollowUps:6
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Electrical gremlins have been affecting us on our trip up the red centre and the symptoms are as follows:

1) Fridge (Dometic RM 7401) appears to run ok on gas but is useless on 230V to the point where the fridge contents warm up even when turned to coldest setting (works worse than 12v)
2) On 12V it usually manages to maintain temp but sometimes when we pull up there is a buzzing sound coming from the fridge that only stops when we switch to gas or start the vehicile's engine again
3) Electrical element on stove top has completely stopped working (was woking a few days ago)
4) Microwave is 900W but appears to only have output power of 500-600W when compared to cooking\heating times to our 1000W at home
5) Lights appear to only be running off 12v never 230V (if we turn off isolation switch the lights go out)
6) Can't say for sure but I believe heater, toaster & kettle running of 230V plugs are running with less power than normal (could it just be the sib zero mornings seem this way?)
6) Have been on parks main power for 30 hours and our van battery has depleted to low levels even though it was good when we left the last place and drove for 3 hours to get to Yulara. The only thing it should be running is the elec starter on gas for fridge and stove when we are on parks mains shouldn't it?)

To top if off there is also a problem with the second battery in the tow vehicle (09 Colorado). I believe the second battery is not charging because the Waeco fridge attached to it will only run for 5 moins or so before giving a low voltage error

I am trying to figure out what is going on. Is it a 12V or 230V issue with the van? and is there any link to the 2nd battery in the tow vehicle?

As I am in Yulara for the next 4 nights or so and unable to move on what can I do to locate the problems?

What expert do I use to fix these problems - Automotive Elec? normal electrician? both?

Is there any hope of finding someone in Yulara or do I have to wait until I get to Alice Springs early next week? Can someone please recommend someone in either of these locations so we don't get fleeced as we are newbie caravanners.
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Reply By: Roughasguts - Wednesday, Jul 11, 2012 at 21:59

Wednesday, Jul 11, 2012 at 21:59
I think you have some how managed a short between youre 12 volt wiring burning through to the 240v wiring some where in the van. Maybe the 240 volt part of the fridge has died and done some damage there.

But all the same I would be very worried that there maybe some 240 volt leakage to the van body it self mate you don't want an electric shock.

Auto electrition would be a good start to get it sorted.

AnswerID: 490692

Reply By: Ross M - Wednesday, Jul 11, 2012 at 22:56

Wednesday, Jul 11, 2012 at 22:56
Your 240 electrical fuses/overload system may have dirty contacts and not allowing power through to the fridge while on 240 v
Pull the one out which runs the fridge circuit and put one of the others in it's place. A phone charger in the fridge 240v plug will tell you whenyou have the right one out.
Refit the fuse/overload and plug in the fridge and see if it heats and sends heat out the vent. The 12 charger may also work off the same circuit and this will then charge the 12v batteries and the lights will become full bright again.

Have you tried another lead? as it may be faulty and acting as a high resistance. Borrow someones lead as a test.
AnswerID: 490697

Follow Up By: Member - Josh- Wednesday, Jul 11, 2012 at 23:12

Wednesday, Jul 11, 2012 at 23:12
Further to your lead comment. How long is the lead, what is it rated at, do you un coil it fully when using it.

FollowupID: 766074

Reply By: Geoff in SA - Thursday, Jul 12, 2012 at 07:52

Thursday, Jul 12, 2012 at 07:52
Hi OznJb

As an electrician I think your main issue is low voltage.
I will list each item and comment.

Item 1: Fridge is useless on 230 volts. Issue is the fridge has a heater (yes) to make it cold and if the 230 volts is too low then it will not operate correctly. low volts = low heat. Gas is good and 12vdc is ok points to low mains voltage.

Item 2: refer above.

Item 3: May be an issue with the element and not the power. If it was power then it would at least get warm. (see a local sparky)

Item 4: Again it all points to low mains power.

Item 5: most lights run off 12vdc its easier to make it happen when building the van

Item 6: Where are you with Sub Zero temps???? Antarctica?? Again its a low power issue.

Item 7: maybe 2 issues . Again low power not giving the charger the ability to output 14vdc or so to charge the battery or a faulty battery charger. the modern ones like voltage within the range stated on them.

The issue of a short in the van is unlikely. BUT if in doubt have it checked by a Licensed Sparky.
The issue of a poor connection somewhere between the camp power outlet and the van switchboard is a real possibility. If this is the case then an electrical fire may result Not Good at all to have your home burn down around you.

Someone mentioned the power lead for the van>
How long is it?
What size is the lead? It should be a 15 amp lead and as I have seem on many occasions people use a 10 amp lead. How do you know the difference? the earth pin is wider than a 10 amp model. And the cable is a lot heavier. By law the plug inlet on the van must be rated at 15 amps so use a 15 amp lead. and all van parks must have 15 amp outlets.
So if your lead will fit one of you plug outlets at home (domestic outlet) it is only 10 amp.

Power is like water. Less resistance and more pressure.
So a long lead, rated at 10 amps and low voltage at the van park and a possible poor electrical connection somewhere in between can and will cause all the issues noted above.

As I have said spend 50$ on a sparky to have him check it all may be better than a fire and warm spoiled food.

Hope this helps

AnswerID: 490703

Follow Up By: Geoff in SA - Thursday, Jul 12, 2012 at 07:57

Thursday, Jul 12, 2012 at 07:57
woops I read more of you tale of woe

I would recommend a 230 volt sparky and not an automotive one.

And remember tradies love to have a beer and a chat.
Beer = lower price

It should only take an hour tops to check the van
If you get charged more than 60 - 70 bucks you are being fleeced.

If it was me there then my charge would be beer.

and sub zero temps ???? I now see where you are. Yes a little nippy at nites
FollowupID: 766078

Follow Up By: OzNjB - Thursday, Jul 12, 2012 at 11:50

Thursday, Jul 12, 2012 at 11:50
Thanks for your valuable advice Geoff.

Current lead was a 15m 15A lead purchased from Rays Outdoors in Vic. I have now hooked up our second lead which is a 25m 15A lead I got from Bunnings. Just noticed when hooking up the new 25m lead that it is much thicker than the 15m one I had been using. Both were labelled as caravan leads when purchased.

Still confused about the lights and 12V though. I understand how the lights may have to go through the 12v system. But when mains is on how do I know it is using that? Surely it doesn't use 12v from the battery only? Also does the battery get charged from mains or only when hooked up to the car?

Should I only ever turn off the battery switch when towing so that power can only go the fridge? Or should I turn it off at other times??

I will try to wait out the 4 days at Yulara and contact a 230V sparky in Alice Springs to come to the caravan park to check it out. I will get an automotice sparky to check out the second battery in the car. For the next 4 days I'll stay on gas and hook the car up when the battery gets low and run it for 30mins to get some charge back in the van battery.
FollowupID: 766094

Follow Up By: Geoff in SA - Thursday, Jul 12, 2012 at 12:15

Thursday, Jul 12, 2012 at 12:15
most vans only have 12 volt lighting as it works from the battery onl;y
otherwise they need a dual voltage lamp. Not yet invented.

vans usually have a battery charger and this will charge the battery when connected to the 230 volt power.
not all vans charge from the car unless therer is an Anderson Plug or similar.
You need bigger cable to carry the charging current.

I leave my battery always connected and on
FollowupID: 766098

Follow Up By: rooster350 - Thursday, Jul 12, 2012 at 12:30

Thursday, Jul 12, 2012 at 12:30
Some vans have an inverter that converts 240v to 12v and half the van lights run of that and the other half straight from the battery , ours did....I took it out and put all LED lights in running straight from the battery , we mostly free camp so it is much more convenient.
FollowupID: 766099

Reply By: Charlie B2 - Thursday, Jul 12, 2012 at 13:38

Thursday, Jul 12, 2012 at 13:38
Hi OzNjB,

Others have discussed the 240v side of things, so won't go there, except to say that a 240v sparky needs to check whether your power supply/battery charger in the van is working properly.

As far as the vehicle electrics are concerned, one other issue might be to do with your alternator or auxiliary battery set-up in your vehicle. I had a somewhat similar, but certainly not identical, issue with my own truck when the battery isolator went out to lunch and my aux battery died at the same time. The alternator was trying to charge the aux without any success at all, so might be worth checking that circuit and the state of charge of your vehicle aux as well.

Physically and electrically isolate your vehicle from the van as a first step. Unplug the trailer plug and any Anderson plugs you might have.

Then a multi-meter set to read 20 volts across the terminals of both your main battery and your aux with your motor is running and fridge switched off will at least tell you whether anything and what is going into the battery. If the cranking battery is showing charge going in and the aux battery does not, then it's likely there's something wrong with the isolator or the isolator-aux battery wiring or fuses or circuit breakers. If there is a good rate of charge going into the aux. I'd probably run it for an hour like that, then allow to stand, again with the motor and fridge switched off, for a couple of hours before checking both batteries again to see how much charge they've retained. if that's starting to look promising for your aux, then maybe the fridge is the culprit.

If your main vehicle battery is charging OK and your aux isn't, then there could be something wrong in there - sure, a big fridge will draw a fair bit of current but there should still be some current going into the aux. Assuming you've got a good electrical connection and adequate diameter wiring between the tug's charging system and the van battery, AND the isolator and alternator are both working, something should also be going into the van battery too. If that is also an issue, then perhaps something should be done to boost that tug battery-to-van battery charge rate (e.g. bigger diameter wiring or DC-DC charger).

I know that in my own case (above) I drove 200km with my 60L Engel running, only to have the aux run out of grunt an hour after I stopped. A new battery and a new isolator fixed that for me, but I can't predict a similar outcome for you.

Apart from the above, I can only wish you good luck. At Yulara your options might be a bit more limited than if you were in a larger town, so if you can get to The Alice that might provide a few more options.

If you don't feel confident enough to make the checks I've suggested above, by all means have an auto-electrician check it all over for you - he'll be able to load-test your auxiliary battery too and that will give you a definitive answer as to its state of life.

Good luck with it all.

AnswerID: 490723

Reply By: oldtrack123 - Thursday, Jul 12, 2012 at 15:56

Thursday, Jul 12, 2012 at 15:56
Hi OznJb

Problems of apparent low mains voltage are not to be played with
Some bad connection is most likely the cause &THAT CAN LEAD TO FIRE
We have no idea of your van's elecrical set up, so all are just stabbing in the dark
The van is very very unlikely to have fuses in the 240v wiring
Have you seen any signs of heat at connections such:-
as the power input socket on the van?
The 240v main switch/ circuit breaker [if fitted]?
[Try turning the Main Sw /Circuit breaker on & off a few times]
any connections in the extension lead?
The van battery charger is appantly not charging the van battery
Another indication of a serious problem with the 240v, which again could lead to a fire
If you cannot get a well qualified sparky to look at it NOW .I would NOT ATTEMPT TO USE, until it is throughly checked.

Unplug the power input lead NOW.
I am a qualified electrician !!!

AnswerID: 490732

Follow Up By: OzNjB - Thursday, Jul 12, 2012 at 20:02

Thursday, Jul 12, 2012 at 20:02

No sign of heat anywhere and just using the single 15A lead as per regs

I will try to find a sparky as soon as I can and will give the advice of Scrubby below a go. Otherwise it will need to wait until Monday when we get to Alice Springs. We simply can't get there any sooner for other reasons beyond our control currently.
FollowupID: 766151

Reply By: Member - Scrubby (VIC) - Thursday, Jul 12, 2012 at 19:15

Thursday, Jul 12, 2012 at 19:15

Just a thought, but have you put some notices up around the area, the office, toilets/showers, etc. asking for an Electrician ?
There may be one camping nearby.

Good luck,

AnswerID: 490745

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