2001 Lincoln LS keyless remote module

[PoolLinolnLS]

First time here. My son’s 2001 Lincoln LS 2 fobs stopped working at the same time about a month ago. Not the batteries. Local locksmith could not program the unit (this model can not use ignition key programming).
Trying to figure out if the module is bad or a fuse. The red wire is always hot. The yellow never hot.
The manual does not contain verbiage on the fuse location. Help. Thx

 

[joegr]

 

[PoolLinolnLS]

Thank you for the schematics

 

[PoolLinolnLS]

I can’t tell from the schematic if the yellow wire is ever supposed to be hot. When I tested the harness, the red was always hot but the yellow was not

 

[PoolLinolnLS]

… but the yellow was never on even with the ignition on. But I can not find a blown fuse. Any thoughts on the circuits?

 

[joegr]

… but the yellow was never on even with the ignition on. But I can not find a blown fuse. Any thoughts on the circuits?

Why are you expecting battery power on that wire? I don't see any solid yellow wires in the diagram that are power. I see two yellow signal wires. One should have probably 5V on it when you press the memory set button. The other one may have low level pulses when you use the mirror adjustment switch. There are some other wires that are yellow with a stripe. I can't see if there is a stripe in the picture.

 

[supernatural]

Could be a grounding issue. Might be worth checking the ground connections.