I was having trouble starting in the mornings and finally nailed it down to a bad glow plug relay. The GPR was either not putting any current through at all or I was getting extremely hot - hot enough to melt latex gloves.
I did Guzzle's awesome Stancor relay upgrade and I now actually look forward to morning starts. Welcome to guzzle's Stancor GPR replacement Mod Web Page
I ground off the rivets on the old relay and tore it open. The relay design is unimpressive compared to heavier starter relays I've seen. The plate on the left is flipped over and is pushed down onto the two contacts on left and right at the bottom of the bowl. The plate and the contact points are trashed from arcing. The top and bottom points are the activating circuit which is not looking healthy either.