Hi Guys
When the fridge is on the 12v mode, the fuse behind the drivers seat melts, but the fuse doesn't blow. The fuse is the thinner one (the thicker one feeds the Eberspacher).
I've not tested it on 240v, but works fine on gas.
Why would it do this and what do I need to check / replace?
Almost ready for the summer
This has been covered here many times before. If you use the search option above you will find previous discussions.
1) What amp fuse are you using?
2) If they are bullet fuses don't use the plastic ones, they soften and fail. Only use ceramic fuses of the right ampage.
16 amp but plastic butb this has been ok for years. Ordered ceramics.
Did a search but spart from fuse types I didnt see anything else. Is there a specific string I should use to search?
I had the same problem with bullet/torpedo fuses.
The problem was created by VW installing aluminium fuses touching copper connections. A chemical reaction occurs between copper and aluminium over time which builds up a resistance to power flow. It then causes overheating and plastic softens. The other thing that can occur and happened to another fuse to my kitchen unit, was that the power stopped flowing altogether, until the fuse was changed. So if you can, get ceramic fuses that use copper. They are more difficult to find, but they are available on Amazon and ebay.
The usual tip - where you cannot obtain copper fuses, twist the aluminium ones to break the corrosion. Better still replace them, after all they are cheap as chips.
As per Ralf85's reply, the heat is coming from high resistance in the circuit. I had the same problem - a melting fuse - with the fuse that fed both the blower motor and the wiper motor. I couldn't find ceramic fuses, but it felt like this shouldn't happen - a 16A plastic fuse ought to be able to carry close to 16A without melting.
In my case, the source of the high resistance turned out to be a problem with the wire connection into the blade connector. A few strands of the wire had broken, so that the remaining strands weren't really up to carrying the full load and they would heat up enough to melt the fuse. The heat had also baked the insulation on that wire for a good 6 inches.
So check the condition of the wiring - if any of the terminals look corroded or frayed it'll be worth replacing them.
"I'm a man of means, by no means....King of the Road!"
CJH wrote:As per Ralf85's reply, the heat is coming from high resistance in the circuit. I had the same problem - a melting fuse - with the fuse that fed both the blower motor and the wiper motor. I couldn't find ceramic fuses, but it felt like this shouldn't happen - a 16A plastic fuse ought to be able to carry close to 16A without melting.
In my case, the source of the high resistance turned out to be a problem with the wire connection into the blade connector. A few strands of the wire had broken, so that the remaining strands weren't really up to carrying the full load and they would heat up enough to melt the fuse. The heat had also baked the insulation on that wire for a good 6 inches.
So check the condition of the wiring - if any of the terminals look corroded or frayed it'll be worth replacing them.
These old style bullet fuses were always problematic. The spring tension from the holder terminals seems to 'lesson' over time (probably due to heat) and the contact between the fuse ends and holder also becomes tarnished, both of which increase resistance and generate heat. This was the main reason manufactures changed to blade fuse boxes in mid 80's.
The holder 'springs' can be cleaned and re-tensioned. Quality fuses are essential, although called ceramic I think the material is more like Bakelite than pot, however, much harder and more heat resistant than cheap plastic.
If you are concerned about excessive fridge current then check it out by placing an ammeter in place of the fuse. I'm sure the 12volt side should be around 8amps so your meter should be OK.
Thanks Martin. Fuses came today so I'll check the current draw at the weekend. Works well on gas and 240v. Think it'll need a service and thev12v fan mods before France in the summer.
Well...as a fellow Westy owner installed with a similar fridge, I can honestly say we never use ours on 12volts. We use gas 95% of the time unless connected to mains.
California Dreamin wrote:Well...as a fellow Westy owner installed with a similar fridge, I can honestly say we never use ours on 12volts. We use gas 95% of the time unless connected to mains.
Martin
And not too far from me!
So what do you do when travelling? Is it ok to travel with the gas still on?
When travelling I always switch over to 12V. It works really well. Despite others saying it barely works, the option in my westie works just as well as gas and hook up. Makes a huge difference when the temperature goes up and you are driving for several hours.
Ralf85 wrote:When travelling I always switch over to 12V. It works really well. Despite others saying it barely works, the option in my westie works just as well as gas and hook up. Makes a huge difference when the temperature goes up and you are driving for several hours.
So today I had the fridge out. Measured the resistance of the 12v element to 1.7 ohms which I believe is expected. Bought some new ceramic fuses and they still melt so clearly not ceramic but they get really hot! I took the fuse box off and on the rear is evidence of extreme heat between the 12v feed in and the link to the second fuse.
So what do I do now? Try to buy some other fuses? Replace the fuse box?
you should replace the wiring, fusebox , and the relay ... sounds extreme but is the only real option and isnt as bad as it sounds.
the wiring from the main battery to the relay is not man enough, even when new, and now 27+ years on, its old and high resistance. ( no need to replace the trigger from the alternator, just the feed from the battery, via the relay to the fuse box with something capable of handling 20 amps )
a new blade fuse fuse box and a nice new modern relay will see your firdge working as it should providing the 12v element ( and switch) are good, which you say above is all ok.
a 1hour £15 fix.
Mocki wrote:you should replace the wiring, fusebox , and the relay ... sounds extreme but is the only real option and isnt as bad as it sounds.
the wiring from the main battery to the relay is not man enough, even when new, and now 27+ years on, its old and high resistance. ( no need to replace the trigger from the alternator, just the feed from the battery, via the relay to the fuse box with something capable of handling 20 amps )
a new blade fuse fuse box and a nice new modern relay will see your firdge working as it should providing the 12v element ( and switch) are good, which you say above is all ok.
a 1hour £15 fix.
Thanks for the detailed reply. Much appreciated. Could you recommend any fuse boxes, wire and the relay?
