I have not found this exact problem searching the forums, so here goes.
Daughter's 2004 D-II will not lock using fob. When fob used to lock door, horn sounds, but doors do not lock. I checked all the doors and re-checked, they are all closed completely. Fob unlocks all doors normally. I can lock all 4 doors by using dash lock button, then using key to manually lock driver's door when leaving the vehicle, so at least the doors can be locked.
Everything was working just fine until today.
Any thoughts? Is this a door lock actuator problem?

 

I am having same problem. Did you ever find the problem?

 

First, if a horn honks, all your doors are not completely closed, the one that is acting up may need a new lock actuator. So find the door that either isn't always closed all the way, has a bad door switch or bad actuator, this can include the tail gate and the hood.

 

Yeah what Mike said.

A recent post was that someone had some engine work done recently, and somehow the switch under the hood had gotten bent, and then he had the exact same symptoms you have.

 

All my doors and hood are closed. I would think that its the drivers door because when I turn off my disco and open the drivers door the radio won't turn off all doors lock and unlock with inside lock and unlock switch. But I can not find the door pin

 

It is not that the door is not closed but the switch does not see it closed.

 

Where is the switch?

 

in the door lock motors.

I would copy from RAVE, but cannot copy and paste from my virtual XP machine because I haven't had the time to learn how, or get RAVE installed on my Linux box.

 

Hi! Did you find the problem? I am having the same exact problem. Please help me
Brian