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Howdy guys, I've got an '98 Econoline and I'm trying to tap into an under dash Key On wire to wire up my Center Console switches. I've gone through the wiring diagram in my TSM but it doesn't seem to show Key On circuits. Please post pics if you have 'em. In the meantime I'm going to wire in an Override shutoff switch so I don't run down the battery.
If you don't already have a factory EVTM or book of wiring diagrams for your year and chassis get one quickly.
Otherwise find a device or accessory that only powers on when the key is in Run or Accessory, track the wiring powering that device and tap into that circuit. This of course assumes you'll be using this relay to supply a 30 amp source to your added switch panel. Something like the radio or heater control would be perfect examples.
It would be more helpful if you'll describe the anticipated amp draw your added switch panel will experience.
Hi JWD, indeed I have the Electrical Vacuum and Troubleshooting Manual for my '98, the trouble is in the diagrams it doesn't discern Key On power, only Always On. Under the dash it's hard to find the wiring for the radio on account of my shoulders.If I can't find the Y/BK behind the radio I'll wire in the master toggle for now, I can always convert it to a relay later on.
You can always buy a fuse tap and pull the fuse for the radio or blower, and use the fuse tap to pull power from that circuit. I just looked at the diagrams for your van, the first several pages are for the fuse box in the engine compartment, and those are mostly "Hot at all times". It says that in the black rectangle squares at the top of the diagram. Eventually they show the ignition switch wiring, which is fed from the engine compartment fuses and fusible links. After that, you will run into diagrams that have a black rectangle at the top that says "Hot in Run".
Thanks Dave, Whew! It took some doing, but I was able to pull the radio and was first happy to see plenty of extra wire and exposed bullet connectors on each going to it. I discovered a Key On source wire but my bullet connectors in my electrical box were too large. I tried crushing one down to size but I couldn't get the circumference correct. So I broke out my Klein Tools wire stripper and bared the center of the wire in two places, then with a razor knife I fully pulled the insulation from the 1/2 inch strip. Then with the help of a very sharp probe I divided the individual wires that I threaded the new wire through, soldered it and insulated with liquid electrical tape. Not elegant but it was going to be behind the radio. I then ran the 14 gauge lead down alongside the engine doghouse to the driver seat. I then went about wiring up a relay and I was pleased that it all went together. Tomorrow I'm going to re-route some goofed wiring to the console and run a ground lead to the back of the van for the backup alarm. I wire the hot to the reverse light wiring, then use the ground on a switch to defeat, so I don't bother the neighbors..
