1990 B250 Van 360ci... my buddy's stuck in the wash up in Santa Clarita CA. NO START.. but kicks on for a few with starter fluid. led us to the fuel system... Only has 1 black relay, ( it was mounted on firewall drivers side..there's 2 unused connectors that dont seem to have had relays in them) Key ON, it clicks.. but we jumped it anyway to test..#87and #30 and still no fuel pump whir in the tank. Do some models not have an ASD relay?

We were going drop tank/swap pump but pulled the connector back at the gas tank and see no voltage at its green wire... (im guessing green should be 12V needed to power on pump..i see 8.5 volts at its blue wire, is this the fuel sender?)

we dont have/cant find this old van fuel pump wiring diagram..
here's 2 sentences i copied from this Dodge Forum.. not sure what make of them:
"The computer does in fact activate the fuel pump and ASD relay with the key on and while cranking
check the powers going into the fuel pump relay. There should be two wires going into the relay that have battery voltage key on and cranking."

Is it as simple as the relay kicks on and that completes the circuit to power on the electric in-tank fuel pump?
As the tank is plastic, the fuel pump isnt grounded.. thus must need 2 wires one ground/one 12V.. How exactly check for voltage at the tank? Tank connector back to underhood is 1 blue, 1 green, 2 grey
We really could use a color coded wiring diagram..

Thx for any help/push in the right direction.. going poke around the forum/ try again after rain quits

 

i guess i need to ask " What is the correct way to check for voltage back at the gas tank fuel pump ?"

 

The voltage will only be at the pump for a few seconds when the key is first turned to On, or Start. If the engine starts the power remains, if it does not the power stops.

 

this is a big help.. explains why i see no reading at the tank connector..
im reading that if the computer doesnt see the engine start then it shuts down the ASD relay...

but wait.. i am bypass/ shorting out the asd/fuel relay... ?
going back this morning... sigh...

 

Problem solved.. ran one long new wire ziptied under frame to replace +12V green wire from the tank/fuel pump all the way to under hood to connect to the green wire/load side of the ASD relay
...
Had to jump ASD relay #30 & #87 for a minute to let pump run for a bit to fully pressure empty lines.. then started right up..

In-tank pump is loud.. probably on its way out

​​​​​​​Thankful for this forum/resource.. my buddy back out on the highway~! God bless all~!