Am using 53 relays in place of any labeled 53 or 24, BTW.
I've also had gauge blipping caused by intermittent contact / broken wires in 14 pin connector (mentioned above).
Here's the map of the wires. One of the surfaces of the unit has terminal numbers:
Here's 14 pin and hot post mentioned by Stan:
Hope something here helps you ( and me ) solve this flashing problem.
The car I'm having trouble with was the first car I worked on. It didn't get a good 14 pin cleaning 3 years ago, so I'm starting there.