Kenworth t800 no dash lights

Had several lighting problems I posted about earlier, fixed most of those but still have no dash lights. Lights come on when you turn the key on, gauges all work, checked fuses, relays, everything good, don't know what to check next.

 

I was wondering about that, but for 130 dollars I wanted to check every thing else first. Is there a way to test that? Like maybe jump the plug to see if they come on?

 

That's what it ended up being, the dash dimmer switch. That's one headache gone, now I have an air tank leaking and it's actually a pair of tanks together mounted under the battery box, there are none to be found so apparentley they have to make them, 2000 bucks and 2 weeks.

 

If you got a t800 2007 or so , the filter is on the outside under the hood on the passenger side, witch I thought wasn't a very good place for it When we got the truck it didn't even have a filter, so the a/c condenser and heater core were plugged. Had them cleaned and it works much better, you might check that out.