1990 suzuki sidekick red light comes on dash

this is normal changing the config drive you may notice how it changes

for the whole car.?
tall order, the book will about $15 used on fleabay
$4
https://suzukipitstopplus.com/Products/1085-1990-sidekick-service-manual.aspx

that be the real deal.
if you have a system on the car , that you need a schematic,
can do. but you asked for the whole car.
some are here
engine, lighting, transmission,radio. , etc.
and 12 pages, in a pdf?
https://suzukipitstopplus.com/Products/1085-1990-sidekick-service-manual.aspx

There should be a power/normal switch on the console just to the right of the automatic transmission gear selector. (Labeled A/T on my '96, but "power" in my '92.) This switch changes the shift profile of the 4 speed automatic transmission.

Is this a 4 wheel drive or a two wheel drive? I am assuming automatic transmission. If a 2 wheel drive automatic, it isn't designed to be towed four down. READ the owners manual. It needs to be towed on a dolly... backwards! If a 4 wheel drive, it most likely the transfer case wasn't in neutral. Also, read the manual.

This Vehicle was equipped with a factory alarm..the toggle switch is for valet.

it could problem with main connector of headlight or combi switch, pls clean it and re fix it.

have to check the fuses - the significance or the power switch on the lights

it can b fuse or relays or the starter motor if all d light comes on on d dash..these fuse and relays are mostly located in the engine compartment

check that you have the freewheelng hubs engaged, this has to be manually on each front wheel hub
Regards Bill au.

As far as I know the procedure should go something like this...

Stop the vehicle, engage the parking brake and if applicable, get out and turn the hubs on the front wheels from Free, to Lock.(You may not have these on a Suzuki, they may be auto-lockers)

Get back in the vehicle and put the transmission shift selector into Neutral.

If you have a manual transfer case, move the selector-shaft to 4x4-High, or 4x4-Low -- whichever is desired. Now, putting the vehicle in gear with the transfer case is sometimes somewhat difficult. As long as the vehicle's transmission is in neutral, don't worry, the gears inside the transfer case are big and beefy -- Don't be afraid to be rough -- Again as long as the transmission is in neutral. You may also have to disengage the parking brake and slightly let the vehicle roll forward or back with your foot-brake to get the Transfer case to lock into place.

Once 4x4 of the selected High, Or Low range is selected, usually indicated by the vehicle jerking slightly with a slightly loud clank/thud. Move the Transmission selector out of neutral into your desired gear (Drive if Automatic, if Manual, whichever gear you pull out from). and voila! You should now be in 4-Wheel-Drive.

To disengage 4-Wheel-Drive. Just reverse the steps.