Power drop to 12v fridge.

Submitted: Sunday, Sep 28, 2008 at 16:15

ThreadID: 62095 Views:7383 Replies:14 FollowUps:11

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Member - Boo Boo (NSW)

Have just got my bushman fridge back from the repair shop and put it on the slide and turned the power on. It stayed on for a minute or so then it stopped.

After it did this for a few times I checked the power to the female connection from the battery and it was well over 12v.

Checked the power in the fridge cord, no problem.

Turned it on again, still cut out. The I tried it with the multi meter prongs still in the cord while it was on. Bingo the power steadily dropped until it cut out.

Checked all the way back on the wiring to battery same thing.

Cleaned the terminals on the battery and the wires attached to the battery.

Still got the same problem.

The wiring is not the real thin stuff found on trailers.

If I hook it up to 240 through the transformer it works fine.

Any thoughts would be appreciated.

Regards Bob

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Reply By: blue one - Sunday, Sep 28, 2008 at 16:26

Sunday, Sep 28, 2008 at 16:26

Boo,
Have you checked the battery charge?

Cheers

AnswerID: 327512

Follow Up By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 16:36

Sunday, Sep 28, 2008 at 16:36

I put the multi meter on the battery poles and it stayed reasonably steady when the fridge was running.

Its also a fairly new battery.

I am almost thinking that the wire may not be the right size. Although the bloke that sold me the fridge saw the wiring and never made comment.He even put the female connector on.

Regards Bob

FollowupID: 594753

Reply By: furph - Sunday, Sep 28, 2008 at 16:32

Sunday, Sep 28, 2008 at 16:32

Had the same thing myself about 3 months ago. Like your fridge, my Trailblaza will cut out when the battery voltage drops below 10.5v.
With what showed as a fully charged battery, 30mins. later was flat. Like 9v. at the terminals.
Recharged, same thing.
Diagnosis --- battery rahooted.
Only 6 1/2yrs. old. an Exide Supreme. Have replaced with the new Century Overlander, will see how it goes.
furph

AnswerID: 327513

Follow Up By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 16:43

Sunday, Sep 28, 2008 at 16:43

Furph

The rotten thing cuts out at about 10.5, but the battery still reads 12.77.

At the fridge without a load it reads 12.77.

Bob

FollowupID: 594757

Reply By: Affordable Batteries & Radiators - Sunday, Sep 28, 2008 at 16:56

Sunday, Sep 28, 2008 at 16:56

How long is the wire and does it get warm at any spot or join / connector ?

AnswerID: 327517

Follow Up By: Affordable Batteries & Radiators - Sunday, Sep 28, 2008 at 17:01

Sunday, Sep 28, 2008 at 17:01

What is the battery voltage just BEFORE the fridge cuts out ?

FollowupID: 594760

Reply By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 17:09

Sunday, Sep 28, 2008 at 17:09

G'day Derek

There are no hot spots that I can feel and it is 12.41 at the battery poles just before the fridge stopped.

For what its worth the voltage started to climb as soon as the fridge stopped.

Regards Bob

AnswerID: 327520

Follow Up By: Affordable Batteries & Radiators - Sunday, Sep 28, 2008 at 17:27

Sunday, Sep 28, 2008 at 17:27

Great, so battery must be OK.

FollowupID: 594765

Reply By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 17:10

Sunday, Sep 28, 2008 at 17:10

The wire is about 3.5 long.

AnswerID: 327521

Follow Up By: Affordable Batteries & Radiators - Sunday, Sep 28, 2008 at 17:30

Sunday, Sep 28, 2008 at 17:30

Is there any writing or specs on this cable ?

For 3.5m long it must be at least 4,5mm2 core. (About the size of a 3mm drill bit of copper in diameter)

Can you test the voltage at the fridge plug when it cuts out ?

FollowupID: 594768

Follow Up By: Affordable Batteries & Radiators - Sunday, Sep 28, 2008 at 17:33

Sunday, Sep 28, 2008 at 17:33

Have you run this same fridge in the same car and with the same cable ?

What was the repair ?

FollowupID: 594770

Follow Up By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 18:07

Sunday, Sep 28, 2008 at 18:07

Derek

Yes I have run the same frige on same wire prior to repair.

Although it worked really well for a while I had intermittent power problem for a long time and finally it died. The problem was not there when I had the car running.

I don't know what the repair was as my daughter picked it up from Central coast while I was in Tassie.

However nothing lit up on the display.

Based on what you and the reply from 1/2A below say about dia of wire it would appear that I need to get better wiring tomorrow

Bob

FollowupID: 594774

Reply By: Member - 1/2A - Sunday, Sep 28, 2008 at 17:35

Sunday, Sep 28, 2008 at 17:35

From the Bushman user manual:
To ensure correct start and operating conditions , the following cable dimensions must be
observed
CABLE CROSS SECTION MM/2 MAX LENGTH* METRES
2.5 2.5
4.0 4.0
6.0 6.0
* LENGTH MEANS DISTANCE FROM BATTERY TO REFRIGERATOR INLET PLUG
I have two Bushman fridges running in my camper and have absolutely no problems running one as a freezer(-15) and the other as a fridge(0) because the wire size is correct.
Link to Bushman fridge manual

AnswerID: 327524

Follow Up By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 18:01

Sunday, Sep 28, 2008 at 18:01

1/2A

Oh boy, it looks like my wiring is well under size if 4.0 is the diameter of the wire, or does it mean something else?

Bob

FollowupID: 594773

Follow Up By: Member - 1/2A - Sunday, Sep 28, 2008 at 18:15

Sunday, Sep 28, 2008 at 18:15

Yep that's your problem, if its more than 4 metres it needs to be 6mil. The Bushman fridge only uses 3.5 amps I have an Engel in my other camper and that draws 6amps and I have 6 mil cable over 2 metres.

FollowupID: 594775

Reply By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 17:49

Sunday, Sep 28, 2008 at 17:49

Derek

There is no markings or writing on the wire (sourced from auto electrician).

The fridge cut out at 11.08.

Errr, the o/s diameter of the wire according to a 3mm drill and my wifes plastic callipers indicate that it is only 2mm!

Maybe there is a problem in the above information?

Regards Bob

AnswerID: 327526

Follow Up By: Affordable Batteries & Radiators - Sunday, Sep 28, 2008 at 19:28

Sunday, Sep 28, 2008 at 19:28

Let us know the results after you change the cable or connect it directly to the battery.

Regards

Derek

FollowupID: 594785

Reply By: Member - Phil G (SA) - Sunday, Sep 28, 2008 at 18:30

Sunday, Sep 28, 2008 at 18:30

What sort of fuse or circuit breaker are you using? Fuses near the battery pos often corrode.

AnswerID: 327537

Follow Up By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 18:42

Sunday, Sep 28, 2008 at 18:42

Phil the fuse is OK and located near the fridge inside the back of the troopy.

I think Derek and 1/2A may have the solution.

Thanks for the input.

Bob

FollowupID: 594777

Reply By: Member - Boo Boo (NSW) - Sunday, Sep 28, 2008 at 19:57

Sunday, Sep 28, 2008 at 19:57

Derek

I will post results ASAP

Thanks Bob

AnswerID: 327555

Reply By: Jim-Bob - Sunday, Sep 28, 2008 at 20:01

Sunday, Sep 28, 2008 at 20:01

G'day Boo Boo
I also have a Bushman, 1999 model, in my Prado with 6mm2 Pos & neg wires.
I also had the same problem as you have after a repair job, new mounting bracket on pipework.

You said the fridge worked ok on the same wires before repair job.
You say the fridge works ok with the motor running (14.2v approx).

Also the fridge works on 240volts, approx 14.8v dc at female plug.

Check the polarity of the wiring on the inside of the male plug on the end of the fridge, mine was reversed.

I think the low voltage cutout is about 10.8 volts, at which the fridge will not even try to start.

Also is the battery for temp readout ok, in there.

I dont think I live too far from you, so could call me on 4938 6226.

I hope things turn out ok for you.

Safe Travells
Jim-Bob

AnswerID: 327557

Reply By: Maîneÿ (wa) - Sunday, Sep 28, 2008 at 20:47

Sunday, Sep 28, 2008 at 20:47

If the fridge runs on 240v and also runs when the vehicle is running, it shows the compressor is ok, so try connecting the fridge 'direct' to the battery with a 'very short' temporary thick cable & fuse connection, see if it works for you.

The cable sizes mentioned above are MINIMUM recommended sizes and you will get superior compressor performance with larger capacity cable, if you use 10mm² cable you will have no problems and it will only cost a packet of smokes extra over the thinner cable.

Mainey . . .

AnswerID: 327572

Reply By: Matt191 - Sunday, Sep 28, 2008 at 22:19

Sunday, Sep 28, 2008 at 22:19

I had the same problem when I borrowed a mates bushman a few years ago, then I bought an evakool 95L and had the same problem. The solution, I ran a 50amp cable from the aux. battery to the back of the car and fitted an anderson plug.

I cut the cigarette socket off the fridge because they are useless as a critical power supply connector, they rattle loose all the time. I cut my fridge wire down to a metre and put an anderson on that too, power problems are gone.

I also have an 8m 50amp cable made up with anderson plugs, I use it when we camp with the fridge out of the car. I have tested it and I get bugger all voltage drop, it works well.

cheers Matt

AnswerID: 327591

Reply By: puttputt - Sunday, Sep 28, 2008 at 22:25

Sunday, Sep 28, 2008 at 22:25

My Fridgemate was doing same thing, found it to be the cigar lighter type plug was not maintaining a good connection, replaced it and all OK. The way to test it is after the fridge shuts down, twist the plug and if the fridge starts again, then the plug is losing contact and hence power.

Cheers

AnswerID: 327593