When I use the Key FOB or the switches on either door the locks make a sound but the lock rods barely go up or down all the way. And if I continue to try it seems that it gets weaker. All fuses are good. Maybe need new solenoids??

 

It would be odd to have both door locks do that at the same time, not impossible just unlikely

What does the Key feel like when unlocking and locking both doors, if its also hard then you need to lube the systems in both doors

2000 diagram below

I would pull either door panel and unplug the 2 wire connector for the lock actuator, hook wires up to volt meter and see what voltage you get, should be Battery voltage when fob button is pressed
The door buttons are direct to the relays, so if they are also slow then not a RAP module or GEM module issue
And there are 3 relays so unlikely for all 3 to act up at the same time


The systems works by grounding both wires at the actuators via the relays when relays are off
To unlock on 1 wire needs to be changed to 12volt because the other wire is already grounded
To lock the other wire is changed to 12v

The Fob and buttons operate the relays

Fuse 18 in the cab fuse box powers the whole shebang, relays and door locks
And G200, grounds the actuators(no I don't know where that is, lol)
If either has a bad connection then low volts/amps
These they have in common

 

Thanks for the diagram Ron. Bitter cold here in Chicago area so will attempt to remove a door panel at a later date or if I can get the use of a garage.
Both locks work real easy with the key. That said when I pull a panel I will be sure to lube all areas.
thanks again, sir.