12V problem

Yep, certainly is.
Krakka

PS - Earth connections as well.

Thanks Tony, I have gone over the earths and not found a problem there. Cleaned up the posts and terminals a couple of weeks ago, but will give it another check over.
Krakka

Yes then the next step is to see if power is going end to end through the wire & anderson plug/circuit breaker. Ive had wiring fail in the middle - internal corrosion! Its a bummer to locate at times. Best of luck Cheers Tony

PS Had an earth wire on a boat motor once that I cleaned the connection and contact to motor numerous times. Gave up looking for the problem and fliked the wire out of the way. That is when it broke in the middle with only the insulation holding it together. You have to test everything from one end to the other.

Tony, thanks for the ideas. I get the same voltage at a/plug at rear of car as the aux battery in the car, Also get the same voltage at a/plug on camper as the batteries in the camper. When I plug the two a/plugs together, doesn't seem to be any transfer between the batteries.
Krakka

Don't know if you have checked this.....the actual contact, what the wires are attached to with in the case of the andersen plug can be pushed out and you do not make a connection, happened to me last time we were away and I had the same problem. Just make sure they are pushed right in.

Cheers Bruce

Krakka. Yep loks like a problem, my old mind cant see whats happening here! If power is going through the wires then all should be fine. Me, I find all my faults with a test light never got into anything else. So if you leave the wires connected to your Aux Battery leave the anderson connected and disconnect from the camper batteries, you can still put a test light across + and - and get power ? If so ther would be no reason power would not transfer - the amount would depend on wire size - but it would still transfer I would think. Lets see if someone can pin point it for you as thats all I can say. Cheers tony

Tony, I disconnected the negative lead from both batteries on the camper,connected anderson plug from aux battery in car to anderson plug on camper and had power at camper as it was powering the fridge that was connected to the camper. However the error light on the fridge was flashing and the fridge was continually cycling despite the voltage at the lead plug where it plugs into the fridge was 12.84V. Wire size is battery cable running all the way from aux to camper.
Thanks Tony
Krakka

Cheers Bruce, will check that tomorrow.
Krakka

Thanks Mark, Testing the earth with one probe on the earth bolt and one probe on the chassis, 0 voltage. Will check the plugs tomorrow to make sure they are making proper contact.
Regards
Krakka

I had a problem with my 12 volt aux and I could not work it out either. I was getting 13.8v whilst car was running but my fridge would not work. Volt meter was measuring the correct voltage but I had a bad earth that only showed up when under load. I went to a very helpful shop who used a load tester. I fixed the earth and fixed the problem. Prior to this I never under stood the difference between volts and current. Seems you learn something everyday.

Good luck.

Hi Murray,
Got a bl___y good spark alright, blew the 100A fuse on the trailer. Connectors in the anderson plug were very grotty, cleaned up with brakeclean but will have to wait till I can buy a new fuse tomorrow to see if it is fixed.
Krakka

Howdy Bill, they are soldered. What is a dry joint?

G'day Krakka,
I've gone away from soldering my electrical connections now; where crimping is an alternative..... as is the case with Anderson plugs.

A dry solder joint is a situation where the solder has not properly bonded to both side of the joint. It may physically "hold" together, but because the initial joint was not "wetted", the solder is not completing a good electrical circuit. It's most common on PCBs (printed circuit boards), but can also occur in more robust joints.

Hope this helps explain the situation.

Cheers

Roachie

Howdy Roachie, "but because the initial joint was not wetted"
Could you please explain what you mean by "wetted".
Regards
Krakka

For solder to work properly, the 2 parts need to be cleaned beforehand and tinned (meaning to use flux, like Bakers fluid, heat the individual components and then apply the solder to the component. Once this is done, you introduce the 2 parts that are to be soldered together and then apply more heat so that the 2 components each re-melt their solder so that the whole joint is as one.

Hope this helps..... there is more to soldering than a lot of people realise. I am no expert but have a background of having built up over 500 kits of model NSWGR steam locomotives (HO scale 12 volt powered).

Roachie

Thanks Roachie, much clearer now.
Cheers Krakka

Dry joints also occur when the two pieces you are soldering together move. The result is a joint that looks grainy and dull instead of smooth and bright. This can happen with an Anderson connector where the wire does not fully fill the socket.

For an extra cause - even if the two parts are tinned properly if you do not apply enough heat for the final step then you can get a dry joint with the same visual look as described above.

PeterD

G'day gmd, Both batteries on the camper are the same, both cranking batts. Batt in cruiser is a deep cycle. All are 1 yr old. Batts on camper are on charger 24/7 in garage running fridge when we are not camping. Charger in camper is a 10A Matson.
Charger I use on cruiser is a 25A Ctek.
Where do I get a battery monitor from? What is it?
Krakka

Pete,

I think the battery monitor gmd is talikng about is a load testng device that most battery places have. They attach it to each battery and load test it. This apparently the only way of accurately testing and these gizmos aren't cheap.

You could of course use an hydrometer as I assume they are wet cells. Apparently the given reading of each cell will tell you if it is knackered or not.

You'll need to seek advice from someone far smarter than me as to what the readigs should be.

Cheers,

Jim.

Thanks Jim

Krakka

Hmmm.. somethings throws me here .. cranking batteries in camper to run fridge ?? I do not know the 10A Matson charger so I can not really say anything definitive but you should surely check the water levels in your cranking batteries in the camper .. my guess is that 24/7 on the charger may have cooked them.

Battery monitors come in different kinds .. the commercial ones and the consumer ones. I have two TM500A Xantrex monitors, one for each battery bank (440Ah per bank AGM batteries) and although they are not cheap they help greatly in improving your energy consumption as well as battery life. One also do the testing with a 100 or 200Amp shunt and a multimeter.

From what you say is, and I assume that above info is correct, I have a guess: The Matson 10A is a fixed current charger and your battery is cooked from overcharging. Thats the most logical explanation to me without really seeing the installation.

Check the batteries with a hygrometer. You can also remove tehm from your camper and bring it to a battery place for testing. Thats the first thing I would do before spending more time guessing.

good luck
gmd

Howdy gmd, Sorry, charger is an Amtex 10A 3 step charger, model 9740-12. It was installed by the camper manufacturer. And is designed to be connected indefinately, so I am assuming/hoping the batts aren't cooked.
Thanks for your info, will have a look at the monitors.
Regards
Krakka

Hin Krakka
Before spending money on monitors etc you need to find out exactly where why you are loosing power
Try following steps as set out:
#1 isolate fridge from cruiser bat IE DISCONNECT BAT LEAD.
#2 WITH FRIDGE SWITCHED TO MAX & CONNECTED TO VAN [A] DOES IT RUN OK?? IF so what is voltage @ terminals WHILE RUNNING??
[B] IF NO CHECK WHAT VOLTAGE ARE YOU GETTING @ VAN BATS??
[C] IF VOLTAGE @ BATS OK CHECK BETWEEN POS & NEG LEADS PROGRESSIVELY @ EACH ACCESSABLE POINT[YOU MAY NEED TO REMOVE SOME COVERS OFF PLUGS] TOWARDS FRIDGE .
IF YOU SUDDENLY FIND A SIGNIFICANTLY LOWER VOLTAGE AT SOME POINT ALONG THE PATH THAT WOULD INDICATE THE PROBLEM IS BETWEEN THAT POINT & THE IMMEDIATLY PREVIOUS GOOD READING.[ IT COULD BE DRY SOLDERED JOINT , CORRODED CRIMPED CONNECTION ,SIMPLY POOR DIRTY/LOOSE CONTACTS OR A BROKEN WIRE]
[D]NOTE ALL READING MUST BE MADE WITH FRIDGE CONNECTED @ TURNED ON EVEN IF IT IS NOT RUNNING, ALTERNATIVELY YOU COULD SUBSTITUDE head lamp bulb or some similar type of load
#3 DO NOT REALY ON COUPLING & FRAME FOR NEG LINE USE ,RUN HEAVY NEG CABLE FROM BATS TO FRIDGE

Thanks oldtrack, will have a go in the morning.
Krakka