Chattering GP Relay - Cause?

In the last week I've installed two new GP relays in my M1009. The latest is the Borg Warner type. Turn the key, wait light behavior is normal but as light goes out, relay chatters A LOT. Sure would appreciate some ideas. Many thanks in advance...

Try putting a diode across the small leads. Get a 1N4007 (a general purpose diode from Radio Shack but almost any 1N400? will work). Install it with the anode (the side with the line) to the + side of the relay.

I sure will! Many, many thanks. But what do you think is causing this? (BTW, I sent you an email on a somewhat related matter we discussed previously.)

So, did you determine the chattering you described in your other thread, was in fact, the Glow Plug relay(and not the AC40 relay)? Or, is this another separate problem?

Yes. Good catch. Embarrassingly, the under dash starter relay was apparently functioning normally. It was my new GP relay that was chattering. I replaced it with an even newer, heavier duty relay which is now doing heavier duty chattering. I still haven't determined the root cause and am quite stumped...

Please list the manufacturer and part number of the relay you are using. It sounds like you are either using the wrong relays or have a problem elsewhere that's causing the relay to chatter. Are you 100% sure the relay you are using, has an isolated from ground, mount?(does the relay coil have 2 terminals that are not labeled?)