I'm in my garage working on van, how can I put the steering column back together

'turner arm', you mean the indicators turn switch and stalk?

https://www.google.com/search?q=1999+chevy+van+g20+indicator+stalk

..

Remove all the plastic covers under the column and dash on driver side. Disconnect the column from the steering box under hood. Unplug the wiring harness from it's connection under dash at column. Remove, if any, the bolts/screws securing the seal flange from the floor around column. Remove the bolts on flange at dash level from the flange. remove the column. You'll want to change out the switch and key code sensor before you start this procedure so you can put it back on the new column so the original key will work. Put it back together in the same order as removal and all will be well.

I think this has 2 small diameter white wires that send a signal to allow it to start. if you look under the dash by the steering column you should see the wires. you can try to cut the wires and join the two wires that do not go up the column together to see if this will by pass the key switch.

Replace the dimmer switch and check for burned wires, melted insulation on wires, wires fused together from heat, etc. When the new switch is on, check operation thoroughly before putting the steering column back together. If the headlight switch is also on the column, check it too.

STEERING COLUMN HAS HAS MANY PARTS ON THE INSIDE.IF YOU HAVE PROBLEMS WITH STEERING COLUMN BEST TO REPLACE WITH NEW ONE OR USED ONE IN PRETTY GOOD SHAPE.

You should retrace your steps from when you replaced the steering column. Chances are you have pinched or crushed a wire harness. Be sure to losen the column from the dash and check there too.Also look where the wires leave the column and go up under the dash. It's real easy to scrape insulation when you are working at hooking and unhooking wire harness's.Tape up any bare or suspicious spots,and make sure your connectors are tight and together properly. They normally only go together one way but they could be made to go together improperly, if you weren't paying close attention or in a hurry. The main harness coming from the steering column is probably your culprit.

to whom this may concern did you find a steering column. Are you replacing it in a 1987 dodge pick-up

I think the problem you have is the steering assembly being loose.

To repair this, you must remove the steering wheel and work slowly down the column assembly, removing the indicator switch, ignition switch and other assorted springs and things. Lay out the removed parts in the order and orientation you remove them, take digital pictures or draw sketches at all stages, watch the spring placements. I also unplug the column looms to give you more room by moving the switches away for the area in the column where you are working.

Once you get far enough down the column you will see the three bolts that are loose, hidden in a sub assembly. I have only been able to tighten two of these over the years. This is a common fault.

Rebuild the column using the reverse of the order you removed it.

Good luck

Double ck the wiring connector.

I checked around and did not find a breakdown of the steering coloum.
Here is what I would do in your circumstance:
Go to the public library and look at a Chilton's manual for that model. You can make copies right there and take them home.

Good Luck.