[gtoric]

Several years ago I restored a '67 GP convert; a PHS documented 400 4-sp. The car had suffered the indignity of an engine compartment fire at some point in its life. As a result, the rear body ribbon harness had been damaged (were it lays against the firewall) and respliced. I located a '67 Catalina convert (400 3-sp) in a parts yard and removed the perfect harness for my project. Now the GP has brake lights that go out when the turn signal is activated. The signals still work, but the brake light on the opposite side from the indicated turn go out. The two inboard bulbs don't work at all. Is this a problem with using the body harness wiring from a Cat on the GP, or is this another electrical snafu? I may have to go back to an original GP harness. Are reproduction rear body ribbon harnesses available via the aftermarket, or might I have to locate another used piece?

[gtoric]

Several years ago I restored a '67 GP convert; a PHS documented 400 4-sp. The car had suffered the indignity of an engine compartment fire at some point in its life. As a result, the rear body ribbon harness had been damaged (were it lays against the firewall) and respliced. I located a '67 Catalina convert (400 3-sp) in a parts yard and removed the perfect harness for my project. Now the GP has brake lights that go out when the turn signal is activated. The signals still work, but the brake light on the opposite side from the indicated turn go out. The two inboard bulbs don't work at all. Is this a problem with using the body harness wiring from a Cat on the GP, or is this another electrical snafu? I may have to go back to an original GP harness. Are reproduction rear body ribbon harnesses available via the aftermarket, or might I have to locate another used piece?

[RAJNWDY]

I would think that the two harnesses would be simular. the Cat & Bonneville have the tail lights that go around the top of the rear panel and the Grand Prix has the lights in the rear panel, simular to 66 GTO's. They are both a 3 segment Tail lamp ie. 3 tail w/2 stop. I would look at the plugs and make sure that all wire colors are the same. GM didn't make drastic changes to wiring colors between years. Also I would check the turn signal switch. The brake circuit comes from the fuse block to the brake light switch and then to the directional signal switch. From there it will go to the front, Dash indicators, and rear lights. Check your grounds at the rear of the car too. as one light beams it may be using another bulb for its ground circuit resulting in a non lighting situation. Good luck