I have a 69 XR-7, mid April build, gauge cluster has the red circuit board, dash harness has the black plug, Understand from WCCC site I should have the white plug on the dash harness for that build and the red circuit board. I am not planning on replacing the dash harness, as the only reason I am aware of this is the Tach died and I took the dash apart to sort that out. The harness itself is in good shape and the non cluster components work fine. Someone has been in it previously, as the dash lights are now all LED. I am wondering should I get a replacement gauge cluster circuit board that would be appropriate for the black harness plug or just leave it. The only quirk I have noticed is the turn signal indicators on the dash will light up when I use the brakes. If I need to replace the circuit board, now is the time while I have everything apart. Can I even do that? Or do I need a complete cluster with the blue board? Tach has been converted to three wire so that problem is solved.
If everything in the cluster works properly, leave it alone.
The difference between the red and blue circuits is that a couple of the circuits have been switched and the wiring at the plug is different. The color of the plug doesn’t matter as long as the wires are in the correct locations for the circuit board being used.
Your issue with the signal lights in the cluster coming on with the brakes needs to be researched. Wiring could be bad somewhere or the turn signal switch may be bad.
Hello Galen. The earlier 1969 XR7 dash harness with the Black plug would have a full 18-pin plug that mates to the Blue printed circuit board which also has 18 connections. The later 1969 XR7 dash harness & red circuit board have only 17 pin connections with one space omitted. This red circuit board also was used for 1970 XR7.
If your Black dash harness plug has all 18 pin locations filled & your instrument cluster has the Red circuit board…then there is definitely a mis-match to sort out. The probable solution to that scenario would be swapping to the Blue XR7 printed circuit board. Easy task and only requires a couple of nut drivers & about 30 minutes of time… once the instrument cluster is removed from the dash.