Dometic Fridge - no red light = no piezo/spark?

[VicVan]

A good reason to take it all out eventually, and cleaning up everything. And do the fan upgrades too.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[coastdog]

I’ve had the same issue with the 12 volt igniter that wasn’t used much. It was intermittent depending on temp and humidity. I pulled the fridge and replaced it with new. Worked perfectly after that.

Also performing some maintenance while the fridge is out will make a big difference. This site gives good guidance. http://www.frankcondelli.com/fridge.htm I followed this the first time I removed the fridge and it really improved its performance.

For lighting the fridge as mentioned by someone earlier it helps to run the fridge for 5-10 minutes on 110 or 12 volt, before lighting it on propane. You could also Pre cool over night on 110 v if you are planning ahead and that seems to help the fridge stay colder for some time after switching it to propane. Kind of like refrigeration inertia. The reason that it lights easier after some run time is because the design of the burner chamber at the back of the fridge needs a gentle air flow from the burner box to go up the chimney and out the side of the van. The stock air pump is supposed to slightly pressurize the burner chamber and create this flow to assist the flame ignition. It’s not that efficient and rarely works. You can buy a kit to upgrade the air pump but it’s a slight improvement at best. When you pre cool the fridge on 110 or 12 v you are turning on heating elements that are wrapped around the chimney. Hot chimney equals gentle airflow draw up the chimney equals propane ignition!

You can also get the chimney ‘up flow’ without any pre cooling if you unscrew the burner chamber drain plug located below the fridge and to the left. The intent of this device is to drain water from the burner chamber if water ever went down the chimney. With the drain plug removed and all the van doors; windows; and pop top closed, if you then turn on your ignition to assessory and turn on a heater fan to high, it will push a flow of air into the burner through the drain tube and up the chimney. It’s another trick that I find helpful and gets your fridge running without waiting.

[VicVan]

Thanks for the extra tips !
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[cmayna]

Some people use a small bicycle hand pump at the drain to push air up into the tube. I have a piece of rubber hose that I attach to the drain and then blow a couple puff's of air.

I agree that just using the fridge more than just once a year will help it start up.
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'90 Westy / automatic.
If I'm not working on the camper or my '50 Chebbie truck, I'm either fishing with the wife or smoking Salmon.


Craig

[VicVan]

Well well, it doesn't work anymore.

Turns out I only have a spark when the shore power is plugged in.
I found a new ignitor, I'll install it today.
Anything else around the ignitor I should check to make sure I have a spark? Grounds?

(No need to mention the other while-you're-in-there stuff like changing the fans, there's already plenty of info on that! Just worried about the spark for now).


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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[Vanagon Nut]

I had a look in Bentley camper wiring diagrams and an online 182B service manual but didn't see the fridge auto spark system. I'm sure more detailed info on the auto sparking system is in this forum but that system aside......

The piezo tip needs to be clean as does metal near it. It's not uncommon for that tip and burner to get dirty and/or corroded. So speaking of "grounds", without a clean path between piezo tip and burner (fridge frame metal), no spark.

As was mentioned, the wire between the switch and piezo itself can be an issue. On my 182A on my first Westy, that wire wasn't properly crimped to terminal that enters the manual sparker switch.



Neil.

182B manual light burner diagram. You can see how B is fairly close to the burner flame vent.

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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[davevickery]

I posted the troubleshooting manual for the electronic fridge in some thread. If you really need it, let me know and I'll look for it.

If the sparker is working on 110 but not 12V, that might indicate a loose wire or less than ideal connection in the 12 volt wiring. I would check everything from the battery to the fridge. Undo the connections and clean them, also the fuse behind the driver seat. But you could also try starting the van to see if that higher voltage provides enough current to get the sparker going. That would confirm that you are just not getting enough current to flow to the electronic sparker or the sparker is just wearing out internally.

In the end, you may just need to replace the electronic spark box, but just cleaning up the connections everywhere may do it. You can leave the fridge sitting in the van to test just the sparker after clearning or before putting it all back together. Just hook up the power plug without all the other stuff connected and see if it works.

[VicVan]

Here's what we have:

Based on what I see and what you have told me on this thread, I will now do the following:
1/ replace burnt electrical connector
2/ replace ignitor (it could be that doing 1/ only will fix everything, but I've bought the replacement part already and its non-returnable)
3/ Check and clean the spark electrode.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[Vanagon Nut]

It looks to me like that brown wire is part of the DC heater circuit so it's not related to the LP system that I can see.

If you don't want to take apart the combustion box assembly, if you use the piezo hole as an access, it might be possible to clean the metal at or near the burner flame vent (where spark should "connect", ground) with some medium or fine emery cloth on a narrow wood dowel (chopstick?) but there's a risk that dirt could get deposited inside the burner. Really, it would be best to open up the combustion box to do any related work. Given the spider webs I see, its entirely possible the combustion box has never been cleaned.

It couldn't hurt to clean the connectors associated with the sparking system.

If the auto ignitor is dead, since there's a push rod visible at air pump, could the older style Dometic Piezo could be retrofitted w/o too much hassle?

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[VicVan]

[Vanagon Nut]

You should be able to test that ignitor with it removed from the combustion box. Just clean a spot on the combustion box top portion, hold sparker near that using insulated pliers or similar. IIRC, my rough guess is that the spark should jump a maximum 1/4" gap. you'd obviously need to hook up DC to the electronic ignitor thing. Alternatively, there might be a way to connect that ignitor to a propane BBQ piezo system and test it that way.

Neil.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[VicVan]

I cleaned everything, changed the ignitor.

Neil, I'll find a way to test it on the bench later, to see if it still works or not. I'll keep it as a spare then I guess...
Thanks for your help!

Note on the Aftemarket ignitor (293-113-2019 , http://www.gowesty.com/product/refrigerator/24419/...market-?v=):
There are THREE differences between the original ignitor and the aftermarket one readily available. Can you spot them?

1/ It is slightly smaller in length. The screws are self-tapping and the metal of the fridge is thin, no issue there.
2/ The spark connector (left of the picture): Round on the OEM, regular small spade on the Aftermarket. I slid small screwdriver inside the round spade, squeezed with a needle plier, and bazinga! Rectangular spade.
3/ The 3 colored wires are not in the same order. From left to right:
OEM (black box): + - L
Aftermarket (white)/ + L -
Make sure you connect the wires correctly!

I tested the spark : it works! Spark frequence is lower than before, say 1.8 sparks / second. But it ticks real loud. Good spark.

Thanks all for your help!
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[fxr]

[Vanagon Nut]

[Tobias Duncan]

Show us a picture of the bottom of the ignition module.
If its bad it will be pretty cooked

[VicVan]

[Vanagon Nut]

re: driving with fridge running on LP. I get it for sure. If all the related wiring etc is good/clean, DC element good, the fridge should cool just as well on DC mode. Albeit w/o the use of the thermostat. My last Dometic would blow out sometimes while driving with on the LP mode. I think the fault lay at the really old thermocouple at combustion box. Anyway, after a fashion, I just ran it on DC mode while driving and wired up the fridge to run off the aux battery under driver seat when engine was off. (for short durations obviously)

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[coastdog]

Driving with the LP cooling the fridge.
If you have the 12 volt igniter and the push button is ‘in’ it will re ignite immediately if the flame goes out. This is one of the advantages of the electric igniter over the manual kind. One thing to watch with the electric igniter is if you have the igniter button ‘in’ the igniter will come on if you run out of propane and remain on until either it fails or the power source dies. Found mine clicking away one morning. As such if driving on LP I only have the igniter button ‘in’ while driving. Once stopped and camping I push the other buttons to get the igniter button to pop out.

My experience is that the fridge gets coldest when plugged into 110v so I usually do that the night before heading out which also assists with a propane start.

[cmayna]

Glad this thread was created for yesterday afternoon, I got bored and decided to try firing up the fridge on LP while sitting in the driveway and without starting the fridge on AC first. Red light for a brief moment, then no red light. Again, this was in a warm camper with no pre chill exercise via AC.

Gave up for the night and then tried this morning while very cool outside and it whoola, fired right up. So, next time think I'll just remember to pre-chill via AC, go to DC when starting the drive and then LP when we stop for the night.

Yes, I also think it would be good to pull the fridge to clean the combustion chamber, check the fan or upgrade it, etc.
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'90 Westy / automatic.
If I'm not working on the camper or my '50 Chebbie truck, I'm either fishing with the wife or smoking Salmon.


Craig

[9.5isCanadian]

Well finally got off my butt and decided it was time I got my fridge to work on propane.
Yanked it out to check for spark action in the fire box.
Probably needs cleaning anyway.........

Working great now

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9 1/2 - missing a few pieces.

1987 Getaway Hightop
1980 Sunroof Vanagon
2018 BMW R Nine T
2012 Golf tdi