I connected 2 meters, one to each grid relay while the truck was still cold this morning. They definitely do alternate one at a time.
Fri 23 Dec 2011
Thu 22 Dec 2011
I turned the ignition on but left the engine off. Then I used these jumpers to activate the grid relays myself. Each relay was sticking!!! Sometimes both of them would stick in the on position for 10 to 20 seconds at the same time!!