Let's try a 90, should be similar. 2 wires go to the external (to the tank) switch on the oil tank, back side, near the block where you can't see it..... Inside is a float with a magnet attached. Magnet controls switch position. If magnet falls off, which apparently it is known to do, you can't get proper operation. Fails are shorts. If you find the two identically colored wires, I keep thinking light blue, white stripe, measuring between them at the bayonet connection to the wiring harness if you have a short circuit you have your fail. I don't know how to retrieve the magnet. But you can bet a knowledgeable guy will read my jibberish and jump on me for being wrong and in the process you will get a correct answer. Grin.