88 GMC Sierra Classic R3500

[spc13b]

So I bought this truck from a older gentleman up the road from me.  It has been sitting for 6-8 years.  It is the 7.4 TBI and TH400.  he had told me that it would crank but was having a problem where it would not start.  I was assuming bad fuel pumps.  It has dual tanks so I purchased 2 new tanks, 2 new fuel pumps and sending units, new tank selector switch, new tank selector valve, 2 new fuel pump relays. I have gotten the new fuel tank selector switch installed in the dash.  I havent gotten anything else installed yet.  We have had a lot of rain this last week.  

 

Today I turned the key on and tested the orange wire on the plug for the fuel pump relay.  I have 2 relays on the fire wall.  One of them tested at 12.15 V and the other orange wire on the other relay was dead @ 0 V.  I switched the fuel tank selector switch to the other tank and it was the same voltage on the same relays.  in the Attached picture the orange relay plug on the left has the 12.15 v 

 

Does anyone have any idea why the orange wire on the right relay plug would be 0 v?

Edited May 3, 2024 by spc13b