Relay Interference

[johnerrington]

I think we now need a schematic.

How to make a schematic you can post.

When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explaining how to add the image to your post. Its easy. Having created the image all you need to do is : Save the image somewhere convenient - maybe your desktop Start your post, and place the cursor (insertion point) where you want the image to be shown; [upload image to forum] 3: click th…

Also I'd strongly suspect a grounding issue. Have you kept the high current gounds seperate as shown here?

skillbank: Experiments and projects with an Arduino microcontroller