clearance lights and tail lights

[Scottyh47]

Ok, so I have a 2009 International CE 300 with the maxxforce DT. Whenever the driver hits a bump the clearance lights go out. turn key off and back on, the lights come back on... we have changed the on/off switch, the turn signal switch (because you can turn on the clearance lights with it). and have looked at every single connector / wire around the interior top of the bus.... nothing looks bad. changed relays with new ones, changed the circuit breakers, still everytime you hit a bump they go out. We have simulated bumps by shaking every wire harness we can find on the engine, underneath, behind loading lights, and marker lights. Then we notice that the rear parking lights also go out when you hit a bump and reset when you turn off and turn on. SO we had a brite idea and changed the body controller and dash with a sister bus. Guess what it still happens. you can also add that we took off the fuse box and checked all connectors and fuse connections in case of water intrusion, the thing looked brand new... every connection is a lil dusty but looks brand new, nothing melted, corroded, nor loose. I am about to destroy this bus. anyone got a clue??

[Studedude]

Had the same problem (different bus) it was the headlight switch.

[ewo1]

Originally Posted by Scottyh47

Ok, so I have a 2009 International CE 300 with the maxxforce DT. Whenever the driver hits a bump the clearance lights go out. turn key off and back on, the lights come back on... we have changed the on/off switch, the turn signal switch (because you can turn on the clearance lights with it). and have looked at every single connector / wire around the interior top of the bus.... nothing looks bad. changed relays with new ones, changed the circuit breakers, still everytime you hit a bump they go out. We have simulated bumps by shaking every wire harness we can find on the engine, underneath, behind loading lights, and marker lights. Then we notice that the rear parking lights also go out when you hit a bump and reset when you turn off and turn on. SO we had a brite idea and changed the body controller and dash with a sister bus. Guess what it still happens. you can also add that we took off the fuse box and checked all connectors and fuse connections in case of water intrusion, the thing looked brand new... every connection is a lil dusty but looks brand new, nothing melted, corroded, nor loose. I am about to destroy this bus. anyone got a clue??

The previous suggestion is a good one, light switch.

you failed to mention checking your grounds. There is a "radiator" ground on the firewall. unscrew it/ clean it and reattach.
visual, just looking at it inspection, is not enough.

Pages 82 & 84, you'll see the grounds I mention.