A bit of background first. We bought our 2012 18.57-5 van second hand about 2 years ago. Had problems turning the fuel select knob on our Dometic 150 litre fridge from AC to DC from the very start. To the point where we have chewed out 2 knobs so far. After our last trip away where I had to use a pair of pliers to turn the shaft of the fuel selector I finally had enough. The problem seems to be fixed now and I would like to share what I found and how I fixed it in case it happens to anyone else.
Basically I pulled the fridge part way out to gain access to the fuel selector at the top of the fridge. To do this I removed power from the van and isolated the van battery. I also found it was easier to work with the fridge door removed. Gave it to SWMBO along with all the shelves, to get them cleaned so got it out of the van completely. Easy to remove as there is one pin at the top hinge to remove and then lift the door off. Removed the fuel selector knob and thermostat knob from the panel and removed the fascia. No screws, just clips at the bottom. Removed the 2 screws at the bottom of the fridge. The panel that runs along the bottom of the fridge will probably fall out when you move the fridge. At least mine did. Just remember to replace it before you reinstall the screws as it fits in between the bottom door hinge and the bottom lip of the fridge. If you don't you will have to remove the screws again to fit it. Ask me how I know! Then remove the 2 screws at the top of the fridge. Now you may be tempted to pull the fridge toward you at this point but don't. If you try it will not move far and you will spend a lot of time trying to work out where it is stuck. Again, ask me how I know! Go outside and remove the bottom vent for the fridge and disconnect the 12 volt DC wires from the terminal block on the back of the fridge. Now slide the fridge out part way until the plastic cover over the electrical connections on the top of the fridge is exposed. There are 3 screws to remove for the cover and the cover itself is a bugger of a thing to get off. Needs some tender persuasion so be careful! Now the fuel selector switch is exposed.
Upon investigation the problem with the switch was pretty obvious and I suspect it never really worked properly from day one. Makes me wonder how many knobs the previous owner went through. The switch itself is a plastic cam connected at the end to the gas valve by a "V" shaped clip. The electric connections are made as the cam turns, going from AC through gas to DC and at the same time the gas valve goes from off to on to off as the knob turns. The problem is that as the knob turns the tabs on the V clip are gouging grooves into the bottom of the mounting bracket and it is of course hard to turn!
The fix was to bend the tabs on the V clip up a little more so that they cleared the bracket and turning the knob became very easy. No major work required and no replacement parts needed, well except for what I hope will now be the LAST EVER fuel selector knob. Selecting the different sources for the fridge is now very smooth and easy to feel where the different settings are.
Then of course you just need to put the fridge back together in the reverse order you took it apart, remembering to reconnect the 12 volt wiring at the back and replacing the nice clean door back on its hinge. It is also worth checking if you have a fan fitted in the cavity behind the fridge, usually behind the top vent, to make sure the wires did not become unplugged during the pushing and shoving. Yes, mine did!
I hope this story helps those of you who may have problems with your fridge in the future. Initially I found it a bit daunting but once I started pulling panels off it really wasn't hard to move the fridge out to work on it. While I am not suggesting you should attempt all fridge repairs yourself there are some things like this simple mechanical problem that turned out to be easy to fix and a lot cheaper than paying somebody to do it.
I have included a pic of the guts of the fuel selector from another old post on this forum. I forgot to take my own pics. I know. Dumb arse.
Cheers, Mike
Basically I pulled the fridge part way out to gain access to the fuel selector at the top of the fridge. To do this I removed power from the van and isolated the van battery. I also found it was easier to work with the fridge door removed. Gave it to SWMBO along with all the shelves, to get them cleaned so got it out of the van completely. Easy to remove as there is one pin at the top hinge to remove and then lift the door off. Removed the fuel selector knob and thermostat knob from the panel and removed the fascia. No screws, just clips at the bottom. Removed the 2 screws at the bottom of the fridge. The panel that runs along the bottom of the fridge will probably fall out when you move the fridge. At least mine did. Just remember to replace it before you reinstall the screws as it fits in between the bottom door hinge and the bottom lip of the fridge. If you don't you will have to remove the screws again to fit it. Ask me how I know! Then remove the 2 screws at the top of the fridge. Now you may be tempted to pull the fridge toward you at this point but don't. If you try it will not move far and you will spend a lot of time trying to work out where it is stuck. Again, ask me how I know! Go outside and remove the bottom vent for the fridge and disconnect the 12 volt DC wires from the terminal block on the back of the fridge. Now slide the fridge out part way until the plastic cover over the electrical connections on the top of the fridge is exposed. There are 3 screws to remove for the cover and the cover itself is a bugger of a thing to get off. Needs some tender persuasion so be careful! Now the fuel selector switch is exposed.
Upon investigation the problem with the switch was pretty obvious and I suspect it never really worked properly from day one. Makes me wonder how many knobs the previous owner went through. The switch itself is a plastic cam connected at the end to the gas valve by a "V" shaped clip. The electric connections are made as the cam turns, going from AC through gas to DC and at the same time the gas valve goes from off to on to off as the knob turns. The problem is that as the knob turns the tabs on the V clip are gouging grooves into the bottom of the mounting bracket and it is of course hard to turn!
The fix was to bend the tabs on the V clip up a little more so that they cleared the bracket and turning the knob became very easy. No major work required and no replacement parts needed, well except for what I hope will now be the LAST EVER fuel selector knob. Selecting the different sources for the fridge is now very smooth and easy to feel where the different settings are.
Then of course you just need to put the fridge back together in the reverse order you took it apart, remembering to reconnect the 12 volt wiring at the back and replacing the nice clean door back on its hinge. It is also worth checking if you have a fan fitted in the cavity behind the fridge, usually behind the top vent, to make sure the wires did not become unplugged during the pushing and shoving. Yes, mine did!
I hope this story helps those of you who may have problems with your fridge in the future. Initially I found it a bit daunting but once I started pulling panels off it really wasn't hard to move the fridge out to work on it. While I am not suggesting you should attempt all fridge repairs yourself there are some things like this simple mechanical problem that turned out to be easy to fix and a lot cheaper than paying somebody to do it.
I have included a pic of the guts of the fuel selector from another old post on this forum. I forgot to take my own pics. I know. Dumb arse.
Cheers, Mike
