should the voltage at fuel pump grey wire always read 12volts or drop to 5volts after a few seconds after key is turned on?
If the gray wire has 12 volts,and then drop,s to 5 volt,s,may be check the fuel relay,or the pump,could be locked up causing the drop in voltage.
has new relay.....
Can you hear pump when you turn key?
is very quiet, i tested 12 volts at fuse panel & now 12 volts at harness dropping to 8 volts under same conditions as first stated above, it is also the second brand new fuel pump. I'm starting to wonder if the grey wire to the pump harness needs replacing from fuse panel to harness. I'm going to check the continuity on it first
Looking for a Used C/K 1500 in your area?
CarGurus has 868 nationwide C/K 1500 listings starting at $2,500.
Search Chevrolet C/K 1500 Questions
Chevrolet C/K 1500 Experts