Cat 777D Mining Truck

[modelman]

JensR-thanks for the link-I read that and may give it a try. However,that doesn't make sense to me strictly from and electrical point of view and seems like a good way to ruin a radio but it is no good to me as it is. I already have the limit switches installed and the rocker switch will work the dump box but I still have to have an on-off switch for the lights. Live & learn I guess. I was trying to get by with a cheap radio and I suspect it is not going to work.

[JensR]

I cannot really comment on the wiring issue, as I don't know how it looks inside.

However, I do believe that two "half channels" with two servo positions each is all you need:
Channel 3: light on / off
Channel 4: dump bed up / down until limit switch reached.

Anyway, here is someone selling an adapter to get proper three-position control:
http://wantasummit.com/default.aspx
http://www.rccrawler.com/forum/showthread.php?t=307196