I'm working on a 1988 Econoline 350 with a 27' coachmen camper that I recently purchased. It has a fuel injected 460. It would not run when I brought it home. I found that I can remove the eec relay and jump it and it starts and runs fine which led me to believe the relay was bad however, new relay did not solve the issue...

With the relay completely removed and the key in the on position I am getting 2.5 volts when checking to the negative side of the passenger side battery. I am getting 2.5 volts at the fuel relay on the switch/control side of the relay and I need to know where to even begin looking for this backfeed voltage.

I can understand a switch being bad or a fuseable link or bad connection but I don't know what to do with voltage backfeed. Any ideas would be greatly appreciated. Thanks