5 volt grounding problems

[endgrainguy]

I seem to have a weak electrical connection between 5V+ and 5V-. I shouldn't have any at all right? The problem shows itself in my series wired , normally closed limit switch circuit, via continuity tester, even with all power off. The switches don't go entierely off when triggered --they dim considerably, but still glow abit. If I disconnect parallel cable from BOB, they go off when triggered . Or if I disconnect one end of circuit from BOB, they go off when triggered . This isn't right, is it? They should go off when triggered with system all wired up, ready to run? Also, this may explain my problem getting a relay board to start my spindle. The wires that hook to the relay board switch from .09 V to 3.8 when Mach3 switches them low to high. It should be at 0, not .09, right? I want to verify that this is abnormal, and if it is how to fix it. Thanks!

[woffler]

test to see if you have continuity to ground to your electrical case from your limit switch wiring.Make sure you have everything connected and power supply off and unplugged.There should be no continuity if there is then you have a ground loop. So then you need to find it start at the the ground connections the wiring from the limit swithces should go to pc ground and not to case ground ie were the power supply ground is and the 110v olt ground is .if this is not it start removing drivers one by one from the case and keep checking to see if you lose the ground loop you dont disconnect any wiring your just looking to see when you remove the item from the case base to see if you loose the ground loop.all items should be mounted so as not to get a ghost ground ie nylon stand offs from the case drivers should be mounted with plastic screws as they can ground through the case of the driver.