RV Repair: 1997 Surburban Furnace, suburban furnace, cardinal 5th wheel

Question
QUESTION: I sold my 1997 Cardinal 5th wheel to my step son. He has a problem with the Furnace not lighting. He says that he thinks he hears gas coming out but the Furnace will not light. I'm not so sure that is happening. I had him check the battery because I believe there is a Sail Switch involved. And the Battery might not be suppling enough Voltage to run the blower motor to open the  Sail Switch,(Older Battery) there fore not allowing the Gas Valve to open. I have not had a chance to go look at it yet. The weather here in Northern Indiana is not the best. Any suggestion will be greatly appreciated.

John



ANSWER: Well chances are that if he is hearing the motor come on and even the gas valve opening then that would mean that there is power getting to the igniter board. That should be where the trouble lies. One thing to try and remember is that when you replace it I recommend a Dinosaur Board as they have a 3 year warranty. There can be other causes but if it was working one day and not the next I would say this is the place to look. Cardinals have I believe atwood furnaces and they look like a shoe box size from the outside. There are either 4 screws or 2 screws holding the face on. Go in there to test for power getting to the board. If there is power there than the board is bad.

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QUESTION: Thanks Bill,

I know for sure it is a Suburban Furnace. You can not access it from outside. The only thing that is on the outside is the intake and exhaust. I bought this rig new and kept it for 10 years. You have to get at it from the return intake grill on the wall inside. It sits on the floor over the duct work. And its bigger than a shoe box. Do you know if the top comes off of the Furnace.
Thanks again.

Answer
Ok a suburban furnace. It should probably be a sf style and for that you will need to disconnect the propane and the electric and remove the exterior exhaust vent. The wires will probably need to be cut, just remember the order they run in. There will be a rear inside cover to take off and a screw in the center after you have it pulled to remove as well. Then it is a matter of sliding it out of the metal case it sits in and then bench testing it. Yellow is the ground and the blue wires need to be hooked together. Use a 12 volt battery and you should be able to test it and see if power gets to the board. If so then the board is bad. On suburban furnaces when you pull the back panel off there will be a roundish electrical device there with 2 wires hooked to it you might want to test to see that power is getting to both sides of it before you cut the wires and pull the furnace. Just one more thing to remember and that is that these have a switch near the igniter board that has an on and an off position. Make sure you don't turn that off when reinstalling it into the cabinet.