Backing out of the garage, the motor quit. Fuel pump had stopped, no fuel feed. Waited, was able to start, drive back into garage. Began diagnosis

Turn on key, engine will crank but not start.

The following are not working:

• Fuel pump does not turn on (no buzzing)
• Red oil light
• Red battery light
• Water temperature gauge
• Cigar lighter with USB in it showing voltage
• Turn signals left or right
• Horn
• Radio

• Fuel level gauge
• Starter motor
• Headlights
• Emergency flashers

It is intermittent. When it does work, everything fires up as normal. While normal, I tried removing fuse #12, but it had no effect. Fuel pump still buzzes, all idiot lights work. To be sure I was not touching the wrong fuse, I removed fuse #1. No change, all works. I put a tester on all fuses. Either show 12v or none on both sides. I ran an extra grounding cable from the battery to the chassis. No joy. I ran a grounding wire from the battery negative terminal to the brown ground wires on the speedometer. No joy. Wiggled all wire connections I could find. No change. Battery is almost new and fully charged.

So I downloaded a wire diagram for a W460 280GE and color-coded it because in black and white it is impossible to follow what wire goes to what component. I upload a copy for others. However, I still cannot see what would power all the items not working. Can't find the common lead. Two questions

1. Does anyone have any idea what to look for next? Grounding seems to be OK, and fuses seem to be uncorroded.
2. If not, where is the fuel relay and can I attach a hot wire to one of the relay wires connected to an illuminated switch mounted on the dashboard, so if the G quits while driving, I can flip the switch and carry on? Would I connect to the relay or directly to the pump, and if so is there any risk of damaging anything?

(LOW-RES-W460-Color-Wire-Diagram.jpg)

LOW-RES-W460-Color-Wire-Diagram.jpg (194KB - 1 downloads)