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

[coastdog]

Spark gap has to be 3/16 of an inch between the ignitor electrode and the gas burner pipe. Too close and the circuit will be continuous and there will be no spark=no light. Too far and the spark will be slow or no spark with slow flash or no flash.

In any case if the spark gap is wrong it won’t lite the burner. Replacing the 33 year old igniter is always a good idea as they do work intermittently and poorly after all those years.

[vantane]

I kept moving the cable the light began to stay lit and then I saw a faint blinking and it continued. This is something.

[vantane]

[latelogan]

Can you more fully explain the problem? is the gas not lighting? (even when the van is cold or hot?)

Does the fridge work on 12V or 120V?
Here is my process that has resulted in a gas light 100% of the time.
-Precool with 120 VAC for 24 hours
-turn the gas valve on at the tank
-inside the van keep the gas valve off
-press the igniter switch and look for the red light to flash (you can hear the spark from either inside the van if its exceptionally quiet OR go to the exhaust port on the outside and listen there.
-if the red-light comes on solid, I take the grill off the side of the cabinet and reseat the igniter cable in the igniter unit and try it again. That has always made the red light return to flashing and sparking. ***
-Press the pilot button in, and slowly turn on the gas valve to the right.
-once the igniter stops and the flame indicator on the panel come on.. hold it for 60 seconds.
- Release the pilot and then set the fridge temp to full.

I have found that the flame works way better driving than the 12 volt, so Im 120 at home and with power hookups, and gas when mobile or without power.

I understand that lots of people have different experiences here.. but this is what works for my rig.

*** I think that the solid red light is the spark unit think that there is a short or some other electrical situation that may harm it so its not wanting to run.
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1991 Westy stock 2.1 auto transmission
1978 Westy (Sold)
1971 Westy (Sold)

[vantane]

Those of you who are interested, I was able to remove the face frame and get a voltage on the switch for the igniter 13.2v the switch is working.

[vantane]

If I can find a way to check voltage at the igniter while it is in the van, then I will determine whether the igniter is faulty or not.

[vantane]

Here are some details. When the fridge is on the bench connected to 12.7v the fan blows and the igniter sparks. The igniter doesn't work after it's installed. I tested the voltage in the van going to the igniter-fans, it reads 13.7v. I tested the fan circuit, it reads 420mA. I tested igniter circuit, it reads 13.2v (fans on).

[vantane]

I re-read your post from back in 2018 and see a resemblance to the problem I'm having. Thank everyone who comment very informative. I have a peculiar situation in that when the van is cold the red light blinks and when I go and it is hot no light not flashing or sparking. But I've done everything except replace the igniter. Would that make sense if the temperature is hot it would affect the resistance hence voltage/Amps etc. and make a new igniter the remedy?

[derekdrew]

Does anybody have a copy of the owner's manual for the 91 style refrigerator? One of my syncro campers is a 91 and I am used to the 1990 and earlier style refrigerators.
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Derek Drew
derekdrew - a t - derekmail - dott - com

[leecat]

Thanks Vic! I think I'm going to try to salvage this fridge as it's in pretty good shape - except for all the missing pieces. I saw the pic of the added manual igniter, interesting but I couldn't bear to drill a hole in this nice faceplate!

The sparkers must be the same for all fridges, so I'm going to try an earlier sparker in this one. Fan blades are bust too and need replaced. I can't quite see how the igniter/light blue ground wires are routed in your earlier pic (your pics were invaluable to me figuring this out, deeply appreciated!), but looks like they're both grounds so should be simple.

I swear 20% of people in this world want to fix up a Vanagon the moment they see one - but the other 80% want to rip parts out and throw them away and then botch as much wiring as they can. Most of the vans I'm trying to bring back to life have been scuttled harder than the Graf Spee. Frustrating!

[VicVan]

I've read of people installing auto-igniters on older fridges, so i fyou have a functional "87 fridge, that might be worth considering. Do a search on the forum.
I have a '90 as well, and indeed there is no igniter at the manual pump. Auto-igniter only. So someone on this forum actually added a manual igniter to their '90 fridge! That way when the autoignitier goes bad, you have a backup.

The autoigniters are easily available at the usual Vanagon vendors, and also at all the RV places.

As for the LED, I imagine you could plug in any off-the-shelf LED and go with it. Good luck!
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[leecat]

Hi John,

Thanks for the info! I do indeed have the new-style fridge, and there apparently is no manual igniter setup from factory behind the push-in air pump on the 90/91 - the case has never been drilled for the mounting screws for one. The wire I'm wondering about actually goes to what's labelled as the 'Safety Valve Button' in the literature.

Is the 'sparker' (mounted at the very bottom back of the fridge, in my first pic) identical to the early fridges? I would think it likely is, in which case I'm sure I can find one and it would only be the availability of the little square red light keeping me from getting this thing running again. Only so many people parting out 90/91 fridges, I would think.

[johnt55]

In the photo, the wire to the igniter is missing because you probably have the new style Dometic with the auto igniter - sweet. (The shaft at the end of the push-in air pump triggers the igniter.) Not sure where you could find a new, replacement igniter. Maybe one of the shops that service the big RV's.

Yes, typical replacement Auto-igniters are available. A great upgrade for the older fridges BTW. About $50 as I recall.
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81' AC Westy

[leecat]

Hey Brain Trust Guys!

Thought I would add to this nice related thread rather than start a new one.

'New-to-me' 1990 'new style' fridge (and thrilled to have it!) - BUT someone has stripped every single thing required for the propane operation. The auto igniter and all related wiring is missing, as is the red square light above the three large push buttons (making the title of this thread even more appropriate - I also have 'no red light' - quite literally! )

The sparker is also missing.

My questions are:

1) Is the 'newer' style auto-igniting fridge worth the effort and $ to save? Or is it simpler just to go to with say the '87 style with manual igniter and not worry about repairing this one? Is the red square light (and sparker) things that can even still be purchased? I see replacement auto igniters are available.

2) Before I hunt through a million wiring diagrams, does anyone know off the top of their head where the black wire from the spade terminal on the side of the 'Safety Valve Button' (red arrows in the pic below) connects to? Is it just a ground? That wire is missing on mine as well.

Sorry, totally new to these fridges! Really appreciate any input on this - enamored with the 90/91 style but have an older one readily available if that's the more practical option.

[coastdog]

Great video! The answer to his wonder about why precooling the fridge on AC makes the fridge easier to light on propane is that the AC heating element in the chimney creates a light air flow up the chiminey which encourages a good air propane mixture for ignition. Without this flow it is up to the operator to get the mixture correct and that’s why some people are good at it and some hate it. Same thing applies if you run it on DC for a short time before lighting on propane.

[VicVan]

I remember watching this video as part of my troubleshooting. Very informative and fun !

You don't look much like your avatar picture though...
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[johnt55]

A little video I did about the Dometic unit.


Link


Cheers!
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81' AC Westy

[HackAl]

Thank you! Used it all day today and it worked like a charm.
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91 Westy.

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[coastdog]

No the igniter button does not need to stay depressed for safe operation. There is a thermocouple in the combustion chamber that is always in contact with the flame. This keeps a gas valve open that will otherwise close if the the thermocouple senses a loss of heat, ie. the flame blew out. It takes a few seconds for the thermocouple to cool and the valve to close and cut off the gas so if your igniter button is depressed and your igniter is not 30 years old (simple fix to a lot of the issues on this thread, clean combustion chamber and install a brand new igniter) the flame will re ignite before the thermocouple cools and the fridge will reignite before you even know it has gone out. This is one of the big advantages to the electronic igniter on the 1991’s over the piezo manually activated igniter on the earlier models.

The thermocouple is the reason that you have to push and hold the button on the mid/left of the control panel when you start the fridge because you are physically holding the thermocouple controlled gas valve open until it senses a flame and stays open as a result.

[HackAl]

On my 91, I'm able to get the fridge working on propane but without the ignitor/flame button on the far right staying depressed.

In other words, I have to stop the clicking and then I see my flame light grow brighter. In the past, the igniter button would stay depressed. However if I keep it depressed now, the flame light never grows. I guess I'm just concerned that if the flame goes out it will not go into reignite mode and gas may build up.

Does that ignitor button need to stay depressed for safe operation?
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91 Westy.

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