How long should the glow plug relay stay on?

I'm afraid to see how long it will stay on so I've chickened out and disconnected it after 20-25 seconds.

I left one of the small wires un"nutted" so I can attatch and detatch it easily, turn on the ignition, attatch wire, relay clicks on and stays on until I disconnect it.

I don't want to burn out my glow plugs.

 

The relay will stay on up to 120 seconds depending on Oil temp and outside temps... Just let it do its job... You will not burn up your glow plugs. They will go out when they are done.

 

According to the manual the glow plugs are "self limiting", so you can't burn them out.

 

X3. I agree with them.

 

Just to be sure, is there a fool proof way to tell which "small" wire goes on which relay post?
I know I have the large wires correct, if it even matters, as I believe they are just the wires going to the glow plug harness in/through the valve covers.
There was no GPR when I bought the truck so I have no reference.
The wires on my '95 are a different color pattern.

 

Doesn't matter. Little wires to the little lugs, big wires to the big lugs...

 

OK, thanks again guys!