I have an International 234 diesel tractor in the shop with an ignition switch wiring issue. The customer bought a new ignition switch for it, which isn't like the original. When her son tried to wire it up the way it looked like to him it should go, everything was on with the key in the off position. So they disconnected the battery and brought it to me. The original switch is a 5-post switch, with the 5 posts being labeled BAT, IG, ST, G1, and G2. The switch has 4 positions from left to right: Heat, Off, On, and Start. The new switch the customer bought has the same 4 positions, but it has 6 posts instead of 5. So I guess I'm just not going to use one of them, which is possible since there are individual wire hookups instead of a molded plugin. But my problem is that I don't know which post not to use. The letters identifying the posts on the new switch aren't like the ones on the old one. If I knew the circuits on the old one, I'd be able to identify which posts did the same thing on the new one. But of course, the old one isn't completing all the circuits, so I can't do that.
Does anyone know what connections are made inside the switch in each of the 4 positions? I already have a wiring diagram for the tractor, so I'm good there. Thanks!