well after some investigating i found that it is for priming the filter. I went through all of the maint records and there are reciepts for about 200 fuel filters!!! I now know that the prev owner loved the smell of diesel and would change the filter once a month.

 

Ahh, it must be wired in paralell. I guess the previous owner didn't know about bumping the starter. For anyone that doesn't know if you bump the starter the lift pump will run for 25 seconds.