hi all can anyone shed any light on this
I have a 20 amp dropper (24-12) I am using a 12v coolbox (5.5 amp)
the dropper gets so hot that its too hot to touch. Is this my coolbox packing up and pulling too many amps or do you think it could be a faulty dropper. this is a brand new dropper but my previous one fried making me think its the coolbox at fault but not being an electronics whizz what do I know.
many thanks all
They do get a bit hot, but shouldn’t be too hot to touch running a 5.5 amp coolbox and I would suspect the coolbox is drawing too much current…pretty easy to check if you have a multimeter.
thanks harry ive got a multi meter but only know how to check the voltage notrhing else. is it easy to do ■■?
Cut/ disconnect one of the wires to the coolbox, put the red multimeter lead in the hole on the meter that says 10A fused (usually) and the black in “-” or “COM” and use the setting that’s to do with current, amps (A) or says 10A, it might have a couple of lower values but you want the 10A one. Connect one lead to each side of where you cut it and it’ll tell you the current.
If you think it’s drawing too much to start with though, touch the wires on a 10A fuse first if it pops, dont use the meter - it wont do it any good and you’ve already found the problem 
if it makes any difference the dropper has a cig plug on it which is fused at 8 amp and that doesnt blow
It maybe wouldn’t mate if it’s the coolbox that’s the problem, I assume there’s no fuse between the two?
no pal theres no fuse between the coolbox and the dropper
god nothing is ever easy 
think ill try plugging something else in and seeing what happens
thanks for your help
I’ve got a 20A dropper that I used to run a heated cup to warm soup up when it was cold and never noticed it get hot and I’d bet that cup pulls more than 5A So I’d suspect the coolbox, have you got anything you could try that would take a lot of power?
You’re welcome anyway.
Wouldn’t it be easier to use the 12 volt socket that in the wagon for this - most of them are fitted with 30 amp droppers as standard these days
cheers
Steve
what a good idea now if only i had a 12v socket i could have saved myself £40
Beware of droppers that say 20a, look for the small print which will often say “20amps peak(for X min) 6amps continuous”. That was often the rating for CB power supplies and droppers to cope with the higher current on transmit and low current on receive.
jc69817:
what a good idea now if only i had a 12v socket i could have saved myself £40
It would have been cheaper to buy two 12v coolboxes, wire them up in series and run the pair off them off of the 24v socket.
Harry Monk:
jc69817:
what a good idea now if only i had a 12v socket i could have saved myself £40It would have been cheaper to buy two 12v coolboxes, wire them up in series and run the pair off them off of the 24v socket.
That put goalposts down my top lip
Where do you have the dropper located - if its sitting in the windscreen on top of the dash the sun can toast it.
no pal its on the floor
darkseeker:
Cut/ disconnect one of the wires to the coolbox, put the red multimeter lead in the hole on the meter that says 10A fused (usually) and the black in “-” or “COM” and use the setting that’s to do with current, amps (A) or says 10A, it might have a couple of lower values but you want the 10A one. Connect one lead to each side of where you cut it and it’ll tell you the current.If you think it’s drawing too much to start with though, touch the wires on a 10A fuse first if it pops, dont use the meter - it wont do it any good and you’ve already found the problem
thanks for the info pal
followed your instructions and think i got a odd reading
0.8 
did i do something wrong
Was the coolbox running with that reading?
IF it’s one of them with loads of aluminium fins on top and a little fan blowing air down them I’d say that’s not far wrong (you’re only running a little motor in the fan), might be worth looking for “shorts” or replacing the wires altogether. Is it still getting hot even though the weather’s been a fair bit cooler this week?
What wattage is it, if it says?
yes pal it was running
dont think it say wattage but def says 5.5A (will check for wattage tomorrow)
yes it is still getting very hot
it doesnt trip or blow a fuse so i think ill prob just leave it
I’d be starting to suspect the dropper at this point to be honest mate, do you run anything else on it and does it do the same?
the other night i had 2 phone chargers plugged into it and a 12v 150 watt inverter running a tv and it wasnt even warm certainly not too hot to touch.
It only gets this hot with the coolbox