Wiring of master switch for gas fridge (1 Viewer)

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Apr 6, 2019
3,937
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Eye, Peterborough, UK
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FourWinds Windsport 6.8L V10
Hi. RM4271 3 way fridge.
Yellow switch on front, how should it be wired!
Three connections. Top one currently black wire and other two are blue. I get voltage between top and middle and top and bottom with switch in OFF position.
No voltage centre connection when in ON position.
Doesn't sound right to me? Suspect switch is probably broken as does not illuminate. Trying to eliminate this wiring before moving on to why no click click click for gas .......
 
Apr 27, 2016
7,005
8,202
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
A picture would help. The pictures of an RM4271 3 way fridge that I've seen look like it's a manual switch between energy sources, not automatic switching. There's no click click click that you get from a 12V spark generator. The gas controls are on the right. Ignition is by a piezoelectric spark generator. You push in and hold the gas knob, then push the red button until there's a loud click, which generates a single spark. I seem to recall there's a small window at the back of the fridge where you can see if the flame has lit. keep clicking until the flame is lit, hold the button in for another minute, and check it doesn't go out when you release the knob.
 
OP
OP
Jev88
Apr 6, 2019
3,937
7,795
Eye, Peterborough, UK
Funster No
59,702
MH
RV
Exp
FourWinds Windsport 6.8L V10
@autorouter
This is the master switch for GAS side of the RM4271 fridge. I need to know how to wire it. Can't trust old one was ever wired correctly.
RM4270 is manual ignitor. RM4271 is automated ignition I believe.

 
Apr 27, 2016
7,005
8,202
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
There should be an ignitor module. Apart from the high voltage terminal that sends the spark, it has three terminals: 12V+, 12V- and L.

The switch has three terminals. The lower two are the on-off function. If power is applied between the top and centre terminals, the switch lamp lights up.

To test the switch, set the meter to ohms or continuity, and check between the lower and centre terminals. There should be about zero when ON, and infinite (Overload) when off. Then check between top and centre terminals. It should be about 100 ohms, whatever the switch position. If it's infinite, the switch lamp has blown.

Switch wiring: lower terminal to earth, centre terminal to the 12V- on the ignitor module, top terminal to the 'L' terminal on the ignitor module.

As an overview, the switch connects the ignitor negative to earth to activate it. The ignitor sends out pulses from the 'L' terminal to the switch lamp. The other end of the lamp connects to the centre terminal internally. When the switch is ON, the pulses go through the lamp, through the centre terminal to the lower terminal (because the switch is ON), and so to earth.

Sorry I can't help with the wiring colours, but if you can see the ignitor module maybe it's possible to work it out.

fridge3.jpg
 
Last edited:
Apr 27, 2016
7,005
8,202
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
I'm no expert on the Dometic range, but I get the impression the same ignitor module is used on many of the different models. So if you need a new ignitor it probably doesn't have to be specific for that fridge model.

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