View Full Version : fixing a 12V fridge
journeyman Mick
23rd April 2005, 11:24 AM
Okay all you electrically knowledgeable out there, I need help! :rolleyes: I've got an old Chescold 3 way fridge (gas, 240V, 12V). Unfortunately it now only works on gas. I've opened it up to have look and found that it just has two heating elements up against the refrigeration gas coils. They're both 100 watts and are the shape and size of a "C" cell battery. I've priced replacements and they're about $120 each :eek: . I only paid $300 for the fridge so $240 is more than I'm willing to spend to get it working again. I was thinking that if I could get some insulated resistance wire I could wind a heating element around the coils in the right spot, solder some tails on and then cover the joins in that glue impregnated shrink wrap tubing to water proof the connection.
Does anyone know where (if) this stuff is available, what types (ratings) I will need and what lengths they need to be? I assume that I will need a given length of wire of a certain resistance to make a 100 watt 12V element and a given length of a different resistance wire for the 240V element.
Thanks in advance,
Mick
Twodogs
23rd April 2005, 06:04 PM
Mick
Forget soldering to the elements it will only melt , use crimp connectors.
For the 240v element you could use a 100w soldering iron or just the element
old irons like the "Birco" are to be found at garage sales etc, Im not sure if they still make them.
For the 12v element you could use the flat wire out of a toaster element and use the mica insulation between layers.
It is not much use measuring the resistance because it will increase when it gets hot and give less power than expected . Experiment with a 12v battery and an ampmeter to find a lenght that will draw 4 amps when hot, then wind two of them in parallel for the element using the mica from the toaster element.
Before you start check the elements are really burnt out , it could be the thermostat.
Good luck
Bill
Daddles
23rd April 2005, 07:29 PM
Now Mick, let's assume you really want this thing to work on that lectricity stuff coz you need it to.
At the moment then, the fridge is worthless, coz it don't run on that zappy stuff.
What will it cost you to buy one that does?
A darned sight more than the $240 to get this one fixed I'm guessing.
So, is the $240 worth it now? Regardless of your original purchase price?
Of couse, you need to consider whether you actually need it to run on agitated electrons.
And you need to consider how well it will run (perhaps a nice, new one is a good move afterall).
Cheers
Richard
I love spending other people's money :D
journeyman Mick
23rd April 2005, 11:34 PM
Richard,
yes, I do need it to run on electricity because you can't run on gas when you're driving! As far as the $$ angle, well, the more money I spend on it or a replacement, the less money I can spend on other things :rolleyes: .
Bill,
the soldering iron and toaster wire is a good idea! I checked both the elements, the 12V one is a dead short and the 240 an open circuit, also there's no thermostat, power wires just go straight to the elements!
Mick
Daddles
23rd April 2005, 11:56 PM
Yeah, I can understand where you're coming from. In the five years I owned the old campervan, it was great being able to keep things cool wherever I was and whatever I was doing. Having a gas OVEN was great too - being able to pull up at a dog trial and offer cold drinks, fresh tea AND freshly warmed croisants made the lace table cloths of the other posers look rather weak.
Go for it mate. Do what ever it costs to give you the most flexibility. You will be enjoying the benefits long after you've forgotten the pain of paying for it.
Cheers
Richard
zathras
24th April 2005, 08:21 AM
Richard,
also there's no thermostat, power wires just go straight to the elements!
Mick
Yup, pretty common on the 3 ways.
The only regulated cooling happens when you are running on gas.
You especially AVOID having to run on 12V for any length of time because they do suck current continuously. No fun cranking an engine with a flat battery :(
vsquizz
24th April 2005, 11:12 AM
Mick, I dunno wether you had the chescold running on DC before but they are very poor performers that will exceed 16 amps on 12 Volt. We used to have 3 of about 45 litre size and would freeze them down on 240 volt, turn them off for travelling then put them on gas for the camp. We used to get more than a week for a 9 kg bottle at 0 deg C, good on gas but useless on 12 volt. If the 240 works it may be worth keeping but from my experience your trying to fix something that was near inoperable in the first place.
Sorry bout that
Cheers
journeyman Mick
24th April 2005, 02:57 PM
Squizzy,
yeah, had it running on all three when I bought it. Only used the 12V on the road, beats having ice melting and getting everything in an esky wet. I've got a 2nd batery set up, a monster Caterpillar one which will run it for about 4 hours.
Mick
Cliff Rogers
24th April 2005, 05:10 PM
G'day.
Have a look around for one or a couple of those 12v travel elements that you can drop in a mug or a pot of soup on the road. They come wired to plug into the cigarette lighter. I don't know what wattage they are but it should tell you on the box. You may need a couple in parallel.
journeyman Mick
24th April 2005, 05:43 PM
I thought of that Cliff, but I was worried that as these are designed to work immersed in water it might overheat. Any ideas? Or just try it and see, they're probably pretty cheap anyway. Might have to check out Supercheap Auto next time I go down the hill.
Mick
David L
25th April 2005, 04:24 PM
Mick, one element each for 12v & 240v so you would probably only need to buy one.
It will work far more efficient on gas, and draws a lot of power from your battery for little benifit. Fill with cold stuff and bring the temp right down before you leave you will be surprised how cold it will stay during the day.
Also roll the unit over a few times before use to get the gas loosened up.
David
ozwinner
25th April 2005, 04:28 PM
Also roll the unit over a few times before use to get the gas loosened up.
David
Please explain????
Al :confused:
outback
25th April 2005, 04:51 PM
I think what he means is, if you have a big feed of Baked Beans, you should roll around a bit and jump up and down to loosen up the gas and expel it. Far better than letting it all out slowly as you drive along. :D
ozwinner
25th April 2005, 04:54 PM
I think what he means is, if you have a big feed of Baked Beans, you should roll around a bit and jump up and down to loosen up the gas and expel it. Far better than letting it all out slowly as you drive along. :D
But you would be far better off running the fridge with it, wouldnt you??
Al :confused:
Twodogs
25th April 2005, 05:04 PM
Mick
I like cliffs idea using a 12v immersion heater but the problem would be transfering the heat to the gas , maybe you could fashion a clamp out of copper to help this.
Another thought I had was some car heaters have a 12v element in them to assist demisting when the engine is cold maybe a visit to the wreckers might help.
Bill
ozwinner
25th April 2005, 05:11 PM
Mick
I like cliffs idea using a 12v immersion heater but the problem would be transfering the heat to the gas ,
Maybe get some of that bog nerds use, you know they use it to glue the heat sink to the hot thing.
Ya know what I mean!!
Al :D
journeyman Mick
25th April 2005, 11:04 PM
Mick, one element each for 12v & 240v so you would probably only need to buy one.
It will work far more efficient on gas, and draws a lot of power from your battery for little benifit. Fill with cold stuff and bring the temp right down before you leave you will be surprised how cold it will stay during the day.
Also roll the unit over a few times before use to get the gas loosened up.
David
David,
unfortunately both elements are gone, the 12V one has a dead short and the 240 is open circuit. :mad:
Mick
David L
26th April 2005, 05:42 PM
Al,
Sorry I should have been more explicit, I was reffering to the refrigerant gas.
The guy at the local gas shop told me that one, apparently the refrigerant settles when the unit is sitting unused for a time and needs to be stirred up to get it moving again for use.
David
journeyman Mick
26th April 2005, 09:02 PM
Al,
Sorry I should have been more explicit, I was reffering to the refrigerant gas.
The guy at the local gas shop told me that one, apparently the refrigerant settles when the unit is sitting unused for a time and needs to be stirred up to get it moving again for use.
David
Yeah, I had a large domestic gas fridge (about 180L) that I sold after it had sat for a few years. The bloke that bought it couldn't get it running. I spoke to a fridgie who told me to tie it on the back of the truck, upside down and take it for a four wheel drive :eek: . It worked fine after that! :)
Mick
Iain
27th April 2005, 08:07 AM
the 12V one has a dead short
I think you will find that there is sod all resistance in an element and there may not be a short at all, like everyone else is saying (I have one too with an inoperative 12v) the 12v is as useless as whatever and any air disturbance around the element will render it useless.
I just freeze a two litre orange juice bottle full of water to get me where I'm going.
journeyman Mick
27th April 2005, 08:59 PM
No. it was definitely working before, used to keep things pretty cool, never measured the resistance before, but I'm pretty sure it would have been more than 0 ohms :rolleyes:
Mick