grounding and shielding is allways very hard to advice from remote without knowing the complete installation.
but shielded motor wires and shielded wires for all limit switches/probes is allways a good start. seperated motor
cables and signal wires is also a help. the main machie body should also have a ground connection.

I also am having a problem with the auto tool zero .  The script is installed and the green light appears on the diagnostic screen under digitize when the router bit is touched with the zeroing plate.  The problem is when you push the button nothing moves--the z axis does not move at all.  I have checked all the wiring and ground and everything appears to be ok.  What is the solution?

Which script are you running?  And if you select Operator/Edit Button Script then click the now flashing Auto Tool Zero button what comes up in the editor window?

CurrentFeed = GetOemDRO(818) 'Get the current feedrate to return to later
CurrentAbsInc = GetOemLED(48) 'Get the current G90/G91 state
CurrentGmode = GetOemDRO(819) 'Get the current G0/G1 state

If GetOemLed (825)=0 Then 'Check to see if the probe is already grounded or faulty
DoOEMButton (1010) 'zero the Z axis so the probe move will start from here
Code "G4 P3" ' this delay gives me time to get from computer to hold probe in place
Code "G90 G31Z-4. F2" 'probing move, can set the feed rate here as well as how far to move
While IsMoving() 'wait while it happens
Wend

'ZProbePos = GetVar(2002) 'get the exact point the probe was hit
'Code "G0 Z" &ZProbePos 'go back to that point, always a very small amount of overrun
'While IsMoving ()
'Wend

Call SetDro (2, .125) ' change .060 to your plate thickness and then adjust for final accuracy
Sleep 200 'Pause for Dro to update.
Code "G1 Z1. F50" 'put the Z retract height you want here, must be greater than the touch plate thickness
While IsMoving ()
Wend
Code "(Z axis is now zeroed)" 'puts this message in the status bar
Code "F" &CurrentFeed 'Returns to prior feed rate
Else
Code "(Z-Plate is grounded, check connection and try again)" 'this goes in the status bar if applicable
End If
If CurrentAbsInc = 0 Then 'if G91 was in effect before then return to it
Code "G91"
End If
If CurrentGMode = 0 Then 'if G0 was in effect before then return to it
Code "G0"
End If   

OK.  And where is this code, is it a button script or stored as a macro?  If the latter then the macro has to be executed from a button script.

It is a button script.

When you press the button, do you get a message in the status bar - (Z-Plate is grounded, check connection and try again) - ?

Have you tried single stepping through the code?  You should be able to see the control flow and where it isn't doing what's expected.

I do get an error message.  It is  "scripter compile error  h"

Hmm.  Well I'm completely baffled I'm afraid.

What do you suggest? Anyone in particular that I could contact that might have the solution?