I am putting in new mechanical op and temp gauges and a 12V fuel gauge. I still have a 24V system so I will come off 1 battery for the 12V for fuel gauge. I'll use toggle switch to turn gauge off. Then I was gona clean up the wiring by removing some toggle switches and a push button switch which were for extra lights and a siren. One of the toggle switches has a piece (About 4") of factory wiring going to it with the # 490 on it. I looked in a schematic I found trying to find out what circuit 490 is. It goes from H on trailer plug to # 24 wire, looks very short. Another schematic for lighting only doesn't show anything there. Since I have a piece of 490 that was under my dash, I assume it used to be back at trailer plug. I haven't looked back there yet to see if I see where it was removed from. What was the H on trailer plug for and why is it shown on 1 schematic and not on the other?
My flashers don't work. To save me time trying to figure out how to troubleshoot this, does any one have a good procedure? There is current coming to steering column because it it lights up when I move lever? My truck is 7-67 delivery date #12631.