RV Repair: RV Furnace, dinosaur fan, furnace fan

Question
QUESTION: Rv Furnace fan will not stop running even w thermost.off. I disconnected thermostat until I get a new one(thinking this was the problem) but it still keeps blowin n blowin with no thermostat attached. Any ideas where to start troubleshootin ?? thanks

ANSWER: Tunc, First off what kind of furnace is it and what year is the coach? If it is an atwood furnace and a fairly new one you might try taking off the outside cover and turning off the on/ off switch. If this is a fan control board I have had them lock and keep the fan running. If it is you will need to replace the igniter board. If it is out of warranty then I recommend using a Dinosaur "Fan 50" plus pins board on it as they have a 3 year warranty and in my opinion one of the best boards you can get these days. If it is a different kind of furnace let me know and I will tell you what to do to get it to quit. Thanks, Bill

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QUESTION: thanks for the reply Bill.
This is an old 84 Toyota Huntsman camper and I've no idea what brand the furnace is,  nuthin fancy thats for sure. I m not helpin myself not being able to answer your question regarding type but its all i know.

Answer
Tunc, The only way this can come on is by power getting from one blue wire to the other. Something is giving it this connection to make it come on. I would check the wires where they go into the furnace and make sure none are touching. After that maybe disconnect one of them at the furnace and see if it still runs. If so then someone has probably wired it wrong. Thanks, Bill