Is you 1999 leSabre a Custom or a Limited. The Customs, I believe, all had manual control HVAC systems which used a
resistor series to vary the fan speed. This goes into the air stream for the heater blower and it's under the relay center
on the firewall in the middle. The relay center has a bolt in the middle that holds it and that can be taken out to gain
some room under it to remove the resistor set. Remove negative battery cable before doing any work. FSM says to
remove the positive jumper cable as well, I assume to make it easier to move the relay center.
Be sure to turn the
HVAC to OFF with the key ON to do any work.
Like Z28 said, the blower motor on a manual system should operate through the high speed circuit which
bypasses the lower 3 speeds.
There are 2 relays that may be involved in the blower speeds as well. I have to check my FSM to be sure
because I recall there's something confusing about the naming.
The automatic system has the blower control module in the same spot.
Why and when did you discover the blend door actuator is not working?
Tell us which system, and I'll list all the fuses to check.
But you may have a relay problem if it's a manual system. The relay #5 or #6 is the one labeled blower motor high speed relay
in the circuit diagram--which always confuses me. If it's not working OR the fused 5D 25 amp in the fuse block
under the left side of dash is blown the blower won't turn on, if I'm reading circuits right.
AND you said you have a problem with actuator, and I noticed the actuator is operated by the same 25 amp fuse
5D in the fuses.
The two relays are confusing in naming. To remove a relay, there's a flat spring underneath that snaps over a ridge when it's pushed in.
So use a steak knife and push under it to lift that flat spring up to let it slide out toward you.
The relay I'm talking about is a relay with 4 connections. It's a single pole, single throw relay. You can check
for the pull in circuit (the electromagnet) continuity. You can take off the little covers carefully and observe the
contacts on the relay. They may be burned from years of use. A little cleaning with sandpaper ... or mini file. I did
that with an AC clutch relay until I could replace it.
The other relay has 5 connections because it's a single pole, double throw, if I've got the name right. One way it's completing
one circuit, and when pulled in the other circuit is connected for the high speed blower.
If you are comfortable with a voltmeter, you can check some of these circuits with the relay pulled out of it's slot.
Good luck. Your problem may be simpler if it's one of the relays... Or the blown 5D fuse.

