Intermittent 182B fridge spark

[RBEmerson]

Our Dometic 182B produces spark intermittently. At this point it's failing more often than not. The symptom is simple: the orange light doesn't blink and the burner doesn't light unless it does. I replaced the igniter; no change in results. The failure rate is the same. The switches work for 110 and 12 volts and cycling the propane switch doesn't make any difference. I suspect some thing is inhibiting the ignitor. Maybe.

We're on the road, making getting parts a challenge. Don't bother to suggest tossing it or a truck replacement. An electric ice chest is a possible alternative but we're tight on space. For the time being we get by with a mix of 110 in state and national parks and 12 while rolling. But that ends in parts of NM, AZ and UT.

What we need is reliable spark. Taking the 182 out, for repairs, is BTDT, tore my t-shirt. Doing it again is not a problem. Well, it's a problem but I'll cope.

BTW with spark, the fridge lights on the first try 90+% of the time.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[davevickery]

I just picked up another electronic fridge for parts. I did some bench testing to see what worked. It wouldn't spark initially. Sometimes nothing happened, sometimes it was a faint solid light and sometimes the red light would kind of go on and off slowly but not normally and not sparking.

So what was the problem? I removed the wire connections going into the electronic sparking module wiggled them and put them back. They must have not had a good connection although they were tight. What I really wanted to do was put some dialectric grease on them but I didn't have any at the time. I have since gotten some and put a small dab on all the electical connections into that module and it sparks reliably now. So I think a lot of the issues are about a good connection.

The one in my van sparks somewhat intermittently and seems related to moisture build up. If I was motivated I would put some dialectric grease on those connections too and see if that solves it. But what I did on that fridge was add a manual piezo sparker to the front of the fridge panel. It is just a generic one from a barBq grill and it is wired from the snap button over to the electronic sparker module and spliced into the same wire that goes to the sparker in the burner box. So it was a super simple install. If the electronic sparker is being fussy, I can just snap the manual one a few times and it lights just as easy.

[RBEmerson]

ARGHHHH!!! 'scuse me while I kick my butt aggressively and forcefully. I believed that tight equals right. What the heck, the wires are going on new tabs. What could possibly go wrong? I even have the grease here.

Having pulled the fridge out once, I understand about how to keep the 12V leads working with fridge out far enough to get to the ignitor leads and dab on grease.

There are three big issues in pulling the fridge. 1) removing the gas collar nut. It's almost a blind job. BTW I burned off the remaining gas in the line by using both stove burners.

Going back in: 2) there are two "shelves" supporting the fridge. Getting the box onto them is a PITA. 3) getting the flue lined up takes some running in and out to get things aligned.

A warning: for at least the '90, there is a single black wire next to the 3 pin connector. Bentley doesn't show it. It's part of the the interlock used while pumping. Use cable ties to keep it with the 3 wire bundle. Otherwise it WILL drop behind the fridge and be a major PITA to recover. DAMHIK.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[VicVan]

Hi

Did you have a look at the combustion chamber ? Down the chimney, where all the action is. Remove the cover, clean everything, light sandpaper on the spark electrode. Should help.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[RBEmerson]

Thanks for the suggestion. It's on my to-do for the next extraction. Something I'd rather not be so good at...
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[RBEmerson]

Good news... cleaning the terminals restored the spark generator thing back to full function.

EDITED: statement about a problem was deleted.
_________________
Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[RBEmerson]

Testing starting the fridge, I found an odd event. Push in the gas button, turn on the gas and the light blinks as expected. Push in the safety button and the light goes dark. But the igniter is still ticking as it should. Pump as usual, and eventually the burner lights off, and the igniter stops ticking. The question is why does the light stop flashing even though the igniter is working as it should?

FWIW we've had no problem with the fridge running and starting it doesn't require voodoo chants to get it lit. It starts as described. The business with the lit is the only thing that isn't quite right. Once we get home, I'll add some insulation.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[davevickery]

It is most likely just not making a clean electrical connection. The little square red led gets a pulse of current every time the electronic sparker sparks.

[RBEmerson]

There's only one connection to the button, a black wire coming off a tab at the switch / valve assembly. Went there, did that on the wire. The other end of the wire ends in a male to female spade connector. That's scrapped, too. I'm starting to think the new model snapper might be the cause. Maybe.

I have AFAIK all of the publicly available docs. There isn't a coherent schematic in the lot.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[davevickery]

Here is a pic of an unmodified fridge. There are 2 wires in the red square led, black and blue. The black wire goes into the igniter module and must be carry the current to the led when the igniter is sparking. The blue is a shared ground wire. Perhaps your aftermarket igniter works a bit different, but I doubt it. Besides pushing the gas valve button should not affect the flashing. Maybe your finger is acting as a ground or something weird. Once mine wasn't flashing but the igniter was sparking and I just wiggled the red plastic square it started flashing again. So for me it it has mostly just been loose or bad connections.

That single black lead from the gas valve goes out to the gray led panel on the stove for the * fridge lit indicator.

[RBEmerson]

Thanks for the photos. They match where I started. In addition to the black, red, and blue wires plus the black off the safety button, there's a green lead My guess is it's a ground for the housing around the thermostat. Again, without a meaningful schematic everything is guesswork. Here's what the new module looks like:

The thing sticking out on the left side is where the HV spark lead goes. Note the marking for the terminals.

While testing the module, the black lead must be connected to the external terminal (or valve) before the module will work. The initial problem with the module came down to dirty contacts. The other connections have been cleaned up, too.

Unfortunately, the button works aas both an electrical switch and a gas valve. Tinkering is not an option. Jamming the button down is ...um... unwise. If the flame goes out, propane will continue to flow. Oops.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[RBEmerson]

I'm 99% confident (Murphy's Law gets the remaining 1%) the problem with the safety button is resolved in the best possible way: Ain't nothin' broke. What's happening is the burner has lit after very few pumps. Lit burner = no light. The safety button has to be held down longer than expected. I now hold it for 30 seconds. I'll play with the time, look for the optimal hold-down time.

One factor in the fast lighting is probably the new igniter module. Whoever makes it has probably boosted the voltage to the spark gap. The flash rate is slower than the original igniter's rate. At a guess, a larger capacitor needs more time to charge up. Looking at the old module, there's a transformer next to the output terminal. The new module may have an improved transformer. All of this probably results in better odds of the burner lighting earlier than before. Which means the light goes out sooner than before. In short, ignition happens much faster than with the old module. Expecting the same performance as before. Seeing something better looks like a problem when, in fact, there is no problem.
_________________
Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[davevickery]

This won't help a lot of people but if you have an electronic piezo Dometic you can add a manual sparker to it. You keep the electronic spark stuff just add a manual spark for backup.

The first time I just added a bbq repair piezo and drilled a hole in the front plastic control panel and mounted it there. But you can just use a non electronic fridges sparker and mount it just like stock and the space behind the plunger is just open on the 90-91 fridges. It just looks a little neater than drilling a hole and putting it somewhere else.

You leave the normal wiring in place and just solder a connection between the manual piezo wire and the electronic spark wire and plug it back in. I put a bit of shrink wrap over the wires and a dab of dielectric grease.

Of course if your sparker isn't reliable you can just fix it, but having a backup way to light the fridge is nice.

And while I have the fridge out I decided to use some muffler wrap on the exhaust. This was only $6 shipped on ebay and is made for motorcycle exhaust so it should help keep the heat from building up behind the cabinet which seems to be the #1 cause of poor cooling. Bench testing all the fridges in my living room at 70 degrees ambient, they all are capable of making ice. It is just when you get them into the cabinet with the sun beating down on the side of the van that they start to struggle.

I am also going to add a fan to the fridge cabinet to try to keep the air back there closer to ambient. I'm thinking a hole saw cut under the sink cabinet at the bottom with a manual switch on a computer fan.

[RBEmerson]

[cmayna]

Good thread. Even though I haven't had any real issues starting my fridge, I also picked up another 182B from a member locally who needed to clean out his garage. Now I have a spare to tinker with. Really like the idea of installing a bbq sparker as a backup.
_________________
'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

[davevickery]

These were the fan upgrades I mentioned. I have a 92mm and a 120mm CPU fan. The 120 does push a lot more air but the 92mm fits perfectly in the existing side vent cutout.

I will probably silicone it to the vent grill and call it good. The 120mm fan would fit there but this fits so perfectly I decided to use it.

I also drilled a 3.5" hole in the cabinet for another 92mm CPU fan
.

This is what it looks like from the other side.

I have both fans oriented to blow air into the cabinet. I tried on prior van sucking air out through the side vent and it worked but didn't seem as effective as when I turned it around and it was blowing in. I should have taken temperature measurements behind the fridge but didn't think to.

With a fan down low on one side and one up top on the hot side of the fridge running off a manual switch, this might work pretty well. You don't need to switch them on unless it is hot summer camping and the fridge still has the stock fan at the bottom that works off a thermostat.

[RBEmerson]

Proof that I slept through an earlier lecture...

Why do I love an uprated fan? The PO put in the GW(?) no doubt expensive monster fan, complete with heat sink frame. But I don't understand why this is A Big Deal. My guess is to unload heat from the radiator. Am I right?

A fan in the vent cutout seems like a natural place but ...um... do I really want the sound of a PC in my ear all night long?

- - - - -

Somewhat related: disconnecting and reconnecting the gas line is probably only a little less difficult than successful brain surgery by braille. Is there a safe mod to move the connection out of its cave behind the fridge?
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[davevickery]

[RBEmerson]

Great thanks for the info!

For one reason and another, we'll ride the Dometic out until it lets go.

I'll look into a fan that won't sound like a PC with a low ball fan.

I forgot that part about the thermostat. NTL at least a fan tucked on the sink's cabinet wall will stir convection up, which isn't a bad thing.

The interior side of the body needs more effective insulation; I guess that's the best time for the fan mods, eh.
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Lord, give me coffee to change the things I can change, and wine to accept the things I can't change.

[cmayna]

Per the guidance of Meesr davevickery, I was able to install a manual igniter into my 182b. Though my electronic sparker seems to work pretty well, I've been wanting to have a backup for .....just in case. Oh and do you see some muffler wrap on the exhaust pipe?

Thanks Dave

_________________
'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