[Richard]

Just to add confusion to this thread, I have owned two Newells. The merge solenoid was wired differently in the two coaches. In the first 1995 # 390, the merge solenoid was activated any time the ignition was on. In the current 1999 #512, the merge switch is only activated by the merge switch on the console.

My point is that there either is some inconsistency in Newell’s thinking on this OR there was a change in thinking along the way.

It might be good to do a bit of testing on your own coach to understand the operation of the merge switch. Easy to do. Put a voltmeter on the activation terminal(s) and run through the different scenarios to understand when the merge is activated.

I should have watched your video first.

Anyhoo, I am using a 300 amp intermittent duty relay for the merge. I think you said yours was 75.

And what is the purpose of the second diode setup on the left side in the video. It only has one in, one out, and I can’t trace the out.