'65 Chevy taillamp wiring issue

[nxtruck]

Guys,
My son's '65 has a wiring issue that doesn't make any sense to me. The problem we're having goes like this: when you pull the headlamp switch out to the 1st detent, the ft. park lamps and the rear running lamps come on like they should. When you pull the headlamp switch out to the 2nd detent, the headlamps come on like they should, but the rear running lamps go out. At first I thought I had a bad h/lamp switch, so I replaced it, but that didn't solve the problem. The PO has a toggle switch wired up and hanging below the dash to turn the rear lamps on, but I'm not sure what he could have screwed up with the factory wiring. According to the shop manual, there is only one wire feeding the rear running lamps, and they do work off of the switch when in park lamp mode. Is there anything obvious that I'm overlooking here?
Thanks in advance!

[FreakyMalo]

Do the front marker lamps stay on when the headlights are on? Maybe the wires were swapped on the switch?

[nxtruck]

Yes, actually they do. That was another thing that stuck out at me. I know that normally the park lights go out when the h/lamps come on with these trucks. I'll give that a look.

[Shooters_7]

Front and rear need to be swapped and that should fix the problem. The front park lamps should have turned off when the headlights are on. Good luck.

[nxtruck]

Yes sir, that sounds like what could have happened. I'll look at it tonite and see what I can find.
Thanks guys!