Both of my 68 heaps have a similar problem ;or is this not a problem. Every time the foot brake is applied the park lights illuminate. What wire where is :crazy: at the incorrect position? Minor issue I 'm sure but would like this corrected . I did none of the wiring on either heap and the wiring appears to be original harness on both. Any pointers for correction would be appreciated. Thanks Larry

hello,,check out the thread toward the bottom of page posted by "crossy", titled "4 way flasher's" not sure if that would be the same problem on a 68 or not but a couple of us have had this happen.:)

I read the thread as suggested of crossys. Sounds right to me . Bet you all are close . Will check it am . Thank You Larry

I didn't read that thread... but try replacing your two tail light bulbe sith new 1157 bulbs... or 2057 if you want slightly brighter brake lights.
This was a fairly common problem 20 years ago or so, the bulb filiments would break and then tough one to the other, creating a short to the other circuit.
If that doesn't do it, I'd install a temp ground wire from the tail light buckets to a known good ground, see if that corrects it. A ground that is only 1/2 good may not be able to handle the added amps that the brake lights draw, and once that happens, it finds the next best path, which would be the tail light circuit. This is esp true on a bed with a wooden floor, and even more-so on a bed that is missing it's wooden floor.