battery > 20 amp fuse > orange relay wire > relay > relay tan/white wire > fuel pump. The orange fuel pump relay wire does not connect to the ecm or anywhere else except the 20 amp fuse that goes to the batery.
You need 5 fuses to make this work correctly with a GM ECM:
a) 20 amp > fuel pump b) 3 amp(sometimes GM used a 10 amp) ECM fuse connected to B1 & C16 hot at all times. This keeps the RAM memory alive when you turn the key off so the learned values are kept. c) 10 amp fuse switched hot in run/crank connected to A6. d) 10 amp switched hot in crank/run to power the injectors. e) from the fuel relay tan/white wire a 1 amp fuse going to B2 << this tells the ECM the fuel pump power is on.
With megasquirt you need 3 fuses:
1) 20 amp for the fuel pump 2) 3 amp switched hot in crank/run going to A6 ( this assumes your using the GM to MS adapter board). 3) 10 amp switched hot in crank/run to power the injectors.
Last edited by efi-diy; 02/20/0902:34 PM.
51 GMC 4.2 turbo Can't solved today's problems using the same technology/thinking that created them
