1988 Chevy dually fuel pump troubleshooting

[WILDERTHANU]

50k OG miles truck.... 454 TBI

Truck has new tanks/pumps/sending units/dash switch/tank selector valve/ both pump relays. They were replaced over a year ago and everything ran perfect.

About 2 months ago with the right tank selected it would not turn on the pump, left tank pump worked fine, so I just ran w the left side only.

Now last week the left started being intermittent.


In the am.. the left tank fuel pump will go on at key turn and stays on for a while.. weird. The right fuel pump I could not get to turn on still. You can hear them kick on usually when key is turned on( r/l whatever one is selected) standard primer function. Could the heat be doing something here.... this is killing me. Its around 100 during the day and 60s at night. I cant get it to do anything in the afternoon.