1985 S-10 Ignition Switch Replacement

I don't think changing the ignition switch is a big problem , there's probably a small hole under the column where you insert a pin to release it , But I think in such an old vehicle there's some wiring problems ie. rust / corrosion at disconnects , you'll have to tear into it with a multi tester to see what's up .

The ignition switch is near the lower end of the steering column, on top of the column itself, near the firewall. The dimmer switch, if activated by the turn signal stalk, is right on top of the ignition switch. First, disconnect the negative battery cable. Then you need to remove the plastic lower steering column cover. Once that's off you'll be able to see the ignition switch, and the dimmer switch. They look like two boxes with a bunch of wires plugged into them. You'll need to lower the steering column by removing the two large nuts from the large bracket holding the steering column to the underside of the dash. If there's a "U" shaped knee bolster you'll need to remove that as well. There's usually four nuts holding that on. Once you've lowered the steering column you can see the bolts securing the ignition switch and dimmer switch to the top of the steering column. You will also see a small rod that goes to each switch. Unhook the rod from the ignition switch after you've removed the bolts holding the switches to the column. Now, test the ignition switch by hooking up the negative battery cable and, using a flat blade screwdriver, slide the ignition switch to the start position. If the engine starts the switch is good. To shut off the engine slide the ignition switch the other direction. Sliding the switch all the way in the other direction will put the switch in the accessory position. Slide the switch one click back to the off position and disconnect the negative battery cable again. A common failure point on GMs is the rack and sector assembly inside the steering column. This is the gizmo that, when you turn the ignition lock to start the engine, moves the rod for the ignition switch to work. Here's a picture of the rack and sector assembly. Hope that helps! Jim

Your ignition switch. Standard part number US105. Jim