Engine won't start - no ignition light

[Aubrey Malcolm-Green]

We've got a 2006 which will not start, the issue is that none of the control lights on the dashboard come on when we turn the key.

Things that have been checked are:

Battery terminal contacts are ok

Earth cables are ok

Fuses and relays seem ok

The engine turns over when we bypass the ignition but it does not fire.

Truck has been idle for several weeks now and we'd love to get it rolling again!

Thanks

Edited January 5, 2013 by sabreman

[Mackpro]

Remove the fuse box cover and turn the key on, to the left of the fuse block in the dash you will see 4 relays (not plugged into the fuse box) , the 4 wire plugs that plug into these relays are labled ' power relay 1" through " power relay 4" . 2 large red wires and 2 small wires on each relay. With key on check each red wire and it should have 12 volts on all red wires. Its hard to get to the red wires so I have a small 'U" shaped stiff wire that slips on my volt meter so I can reach them eaiser. If no voltage on any red wire then voltage problem from starter to cab. If only power on only one red wire per relay then key switch /fuse is bad or the relay itself is bad or the cab ecm (VECU) is bad.