My guess it had some Aftermarket Alarm installed at some point in the past
and it was removed.  It may be a hacked wire mess under the dash.
I'm guessing you do have power locks, so you should be able to get a new
Aftermarket Alarm setup with keyless Entry with the FOBS and all.

Hi,  Yes your Tahoe came with Keyless entry from the Factory. As the
other poster suggested, the Alarm most likely crapped out, and was
somehow bypassed-shut off.

Tough to say what type of alarm, but there will most likely be remnants
of it under the hood (Siren possibly), and under the dash, and will no
doubt make use of a stock Keyless Entry controller impossible, until
this system is completely removed from the truck. They no doubt spliced
into wiring that controls the Door Locks, etc.  Look for little black
boxes near the base of the Steering Columm-under the Dash, with names
like Clifford-Avital-Viper-etc will be a sure clue.

Best-cheapest option is probably going to a good Alarm dealer-installer,
have them remove whatever's left of the old alarm, and install a new
entry level priced Alarm, with its own Keyless Entry Fob.

The Chevy Dealer would no doubt take you to the cleaners $$$$$$.

As for the Windshield Wipers: Before spending any money, use the proper
Torx-Head Bit with Screwdriver, and remove the Black Wiper Control Box
Cover on the Driver's side of the Firewall. Clean down the entire Board
with Contact Cleaner, if grease is laying all over inside, and on a
couple of round Metal Discs, re-distribute that grease onto the Worm
Gear visible.  Do the best visually inspecting the Board. The usual
culprit was the Plug, and solder connections that went to the Board
Just leave a very light thin coat on the Metal Discs. Re-assemble, and
give it a try.

I myself was beginning to get the same erratic problems on my '97 Tahoe
a couple of years ago, and luckily this simple fix-maintainence cured
the problem for me.

If that doesn't solve the problem, you'll need the new Board from Chevy
and do a swap out. Yes, at one time I believe there was a safety recall,
but I believe the free replacement through GM is long gone.  Hope this
helps.  Mark

I would look in your glove box for the RPO list.
That will tell you if you have Remote entry Lock Control.
I bought a used 2000 Silverado, and bought the Key fobs from the dealer.
(Pricy). You may find them on eBay.
But I would check the RPO's first.