Hey guys I just recently sold my flat bed to get a box for my 1990 w250. Me being a dumbass I cut all the tail light wires on it not thinking and in a hurry. There is tons of different wires under the bed because my truck is a wiring disaster thanks to the guy that owned it before me. So I was wondering where the source is where the tail light wires hook up under the dash. I think it will be easier just to rewire the tail lights at this point. Thanks for any advice.

 

Ha...im in that same perdicament right now...hilljack that owend it before me was NOT an electrician...i would also love any help that you guys could provide

 

Haha yupp!

 

Well, I looked up my trusty Haynes diagrams, all 9 pages of them, and ya'll are in for a treat. Unlike the manuals for my Jeeps, that took up one page, these are all over the board. You should be able to trace some of the reverse lamp circuit off your switch on the transmission, seems like that is a white wire (powered off of the 5 amp fuse on the block). Coming off the turn signal switch on the column, look for and trace a dark green/yellow tracer and a brown/yellow tracer. Those should have power out of the flashers on the fuse block, which on all our trucks is loose. The brake switch should have a white/tan tracer bringing power into it from the fuse block. The diagram in Haynes is more than a little frustrating, to say the least. The headlight circuit (or, I guess, tail light) should be a Black/yellow tracer that SHOULD tie into the HL circuit under the hood, but I cannot verify if this diagram is what I've seen on my '91. Sorry I don't have a magic bullet, but maybe this can help you out. Somebody here has the legible diagram and has offered to email it before, so maybe try a search ...

You should have the VSS and the Fuel sender already handled, so once you're south of there, you should be looking at a three wire harness that splits to the tail lights (unless you're gonna run some chicken lights). When I started patching up mine last year, I couldn't believe what I got stuck with from the PO. If you haven't done it already, yank the fusible links and replace with fuses, too.