[LAN2UNOW]

Thankfully my 98 Blazer can be done without the jumpers,
but if you're sure you've taken one wire, put each end into
position #4 and #8 (between to short it out, not just a
wire in each slot as those instructions aren't really, really
clear about that but it needs to be shorted) and are totally
sure they're touching and stay in place while you go to program...

Have patience. Those instructions say 15 seconds, mine says
'up to 30', but I had to sit there and hold both those suckers
for longer than 30 seconds on the RKE fobs. And you MUST
hit both buttons together, not one -hold- other one as that
won't work either. Check the batteries, it's possible a new
one may make a world of difference.

If all that fails, do you have more than one fob and do any
of them snyc up? I have 3 now, 2 in use and one spare. I
picked up one from eBay and it actually responds faster than
the original presumably because the original was used heavily.
So the contacts on the circuit board inside the fob are simply
worn down, the rubber insert is also worn and thus it doesn't
make as good a contact as it used to. I can live with it, but
since I programmed that first it did seem to take nearly a
minute before everything locked/unlocked to show the fob
was sync'ed right!

Your own risk if you mess with the contacts, etc. in the fob
as replacements aren't cheap obviously. Sometimes you can
fix a worn rubber nub on the insert, many times it's the contacts
inside. You can even try to find a way to push on the contacts
directly with the fob open and see how they respond as well.
Might just be time for a new one - if you got one use that as
the primary sync one first.

So patience, hold'em as long as you can before giving up!