Battery Short randomly losing ECM power w/ign on

[Brock]

Unplug the 4 pin power/ground plug from the left side of your ecm, take your low beam bulb out of your headlight, use a couple Male and female butt connectors and 2 pieces of wire to make a harness to run your headlight bulb off that plug...... there is a constant power wire, a ignition wire (this is the one losing connection) and a ground on that plug. That bulb should light up bright, if its dim then the wiring is bad.

Another thing is your ground and power wires run up to your drivers side firewall where your mega fuses are, on the inside of your firewall is the opposite sides to those posts and they can get corroded real bad as well as remove your foot panel by your BCM and look up there.

The ground that goes from the starter to the frame also has the wire attached to the same frame bolt that runs up to your firewall so all must be clean. If you have a ohm meter do a resistance test on all grounds to ensure they are good.

https://www.thetruckersreport.com/trucki...ay.272033/

Hope it's ok to post other forums links because I hijacked this thread over here and documented what I did to find this issue on page 8 I think..... it shows the headlight bulb test too.