1996 Chev Blazer-water in driver's side floor board

Most likely it's the sunroof...youtube how to fix a leaking sunroof

A water leak under the dash could be the heater leaking near the glove box, or a windshield leak, or sometimes the drain tube for that area has gotten plugged up and needs to be cleared out. Most times a little blast of air pressure will do it.
Hope this helps.

There is a tube on either side, and they have a tendancy to get clogged with debris. I would attempt to clean them out. You may also want to remove the wipers, and tale off the top of the wiper module. Leaves, and other debris tends to collect under there, and that's what clogs the drain tubes. Good luck, and let me know how it works out. Thanks.

You could have a windshield that is leaking water. Often this water will trickle down from the bottom/inside of the glass and then down the firewall, under the carpet or floor mat, and to the floor. The way I usually hunt for these is to remove the floor mat or carpet then get a flashlight and lay down in the cab so you can see under the dash area while someone sprays water on the vehicle with a garden hose. Often the leak will show up as a trickle that you can then backtrack to it's source. Another spot to look for is at the cowl in front of the windshield where air for the heater and a/c is pulled into the passenger compartment. The water drain holes in this area can plug up and allow water to overflow into the passenger compartment. Good luck, hope this helps!

shop vac the carpet dry then spray garden hose around both rear doors or around doors and see if you get wet or see a leak. Also spray under vehicle on both sides of car and check for leak.

punch in on your computer 1996 chevy blazer specs. u will get or go to autozone.com.

This could be coming in from a few places. As well as checking seams, i would suggest checking your floor pans... Many times rust will slowly eat thru the floor pans, and allows water to be soaked up... Get the car up in the air ( or climb on under it). Tap on the "floor" from underneath where the rear Foot area would be. If it seems rusty or weak or you can see visable damage. this could be your culprit, even if it isn't rusted through completely. This is a very very common problem with cars in my area , as I live in northern USA. Alot of snow = alot of salt on roads = alot of rusty floor pans :)

This could also be coming from your B - Beams. When your tires displace water. it splashes them against the inside wheel well and tire guard.. Under that guard lies your car body. If this has rust in /on it that has penetrated all the way through, the water is getting thrown "into" the body panels, which is leaking through to your seats. Hope this gave you a little more information on places to look.

use a shop vac to **** out the water

Check with Toyota Parts. I'm sure there is one, but it is unavailable at a retail parts store. Heater cores are pretty much as necessary as the four tires on the outside are. My advice would be to remove the core and check the hose clamps or connections for other issues. You want to be sure that the leak is in the core and not in one of the hose connections. I think that is odd that your driver side floor is wet and not the passenger side. Open the hood and look for coolant hoses attached to the firewall (the sheet metal between your dash and the motor) and see if they are on the driver side or the passenger side.

Is it antifreeeze from heater core or heater core hose leak?  Is the leak pure water, or maybe something else?
Put it in the garage again overnight with an old white towel in the drivers foot well, best if you can find a way to stretch it from drivers seat forwar to firewall and keep it off of floor mat.  Check it before you go to bed,  then in the morning if no leak found yet.  see if the color/location of the spot helps you identify the source.  I think the heater core is under the dash center.  Anti freeze is green/yellow or orange.
good luck