Dometic Servel RGE400 fridge too cold

[GuyCanRV]

Well it's been almost a year now since I revived my RGE400 fridge for a second time.

As I mentioned in my last post about the fridge when I put it together the control
rods were messed up and I didn't want to spend too much time with them.
I was also missing some end caps etc.

So basically I was operating the temperature control blind.
After getting the fridge to work (electricity only) it was far too cold.
So I removed all the food and laid the fridge down to gain access to the control rods
at the back.
I tried turning the rod once again to a lower setting (blind, once again).

Since then I haven't touched the temp control, but the adjustment didn't make a difference.
The fridge is still way too cold. A lot of the food actually freezes!

I'm open to suggestions.
I think the thermostat is probably malfunctioning.
Is there a way to test it/fix it?
There is something else I thought of.
I recall reading somewhere that the thermostat coil that feeds into the fridge from the fins,
can be adjusted. Pulled inside the fridge more or less.
I remember reading that this can be used to adjust the fridge temperature as well.

Again any guidance would be appreciated.

[joebedford]

Have you moved the temperature sensor on the grid fins?

You can unplug it and test the resistance.

[GuyCanRV]

Thanks for helping out Joe.
I don't know if I should lengthen the sensor to make the fridge warmer or colder?
Did you mean unplug the fridge?
How would I test the resistance and what reading should I be looking for?

[joebedford]

AI mean unplug the sensor and check the sensor's resistance.. it's possible it's not working and an ohmmeter will tell you.

[GuyCanRV]

Thanks Joe.
Well I ordered a new thermostat and it arrived today.
I have a couple of questions about it.
There are two pieces of black tape on either side of the unit that seem to be covering something. What are they for? Should I leave them as is?
It came with two tiny rubber 'o rings'. What are they for? Where do they go?
Thanks.

[aftermath]

If the sensor is high up on the fin it will make the temperature in the fridge colder.  Move the sensor down and it should keep things "warmer".  Cold air pools down low so if you have the sensor down low, the cold air will get to it sooner causing the fridge to shut off.  Just the opposite if it is high in the cavity.  Takes longer for the cold air to pool around the sensor, hence it runs longer, hence colder temperatures in general.

[GuyCanRV]

Thanks for helping aftermath.
I tried moving the sensor down all the way to the bottom of the fin
but it didn't help. Fridge is still just as cold as before and the veggies
are freezing.
I think I'm running out of options now?