I replaced my standard harness to XR7, (From engine, to trunk including overhead wiring and passenger side harness. Toggle switches all work and courtesy lights all work). My turn signals no longer work, no sound at all in trunk. When I put the flashers on there is nothing, but something in the sequencer keeps whirring. Are my relays bad? Is the turn signal relay bad? The standard harness had a normal turn signal flasher,(heavy duty), in its wiring. Any suggestions?
What year cougar are you working on, 67 and 68 do not use a turn signal flasher, but the 69 do however they utilize a solid state sequencer so you would not hear a whirring sound.
Coach Jack
I believe he is in another thread and it’s a 1968…if I’m wrong, this won’t apply:
They use a sort of flasher, but they are different from '67 to '68, and NOT interchangeable, or you’ll short out the system. As Coach will tell you, the TS relay works on the load of the lamps for ‘on/off’ cycling. Get the correct one for your '68.
If the whirring sound you hear is the Sequential motor in the trunk, and you have no lights, the motor isn’t connected to the Sequential relay (K8/9), or it is bad. It may not be getting a signal from the turn signal switch as well, so you’ll want to check the white-440 (L) and violet-441 (R) wires at the K8/9 relay for 12v when signalling.
How are the brake lights? This will tell you if you have good bulb grounds and partial K8/9 function (it toggles from brake to TS on the side you are signalling).
I’m working on a 68. Guy who sold me the under dash harness took it from a wrecked '68 XR7
Did your turn signals work before you replaced the harness with the xr7 harness? Post a picture of the “normal turn signal flasher” on your other harness.
Coach Jack
I wouldn’t get too caught up in that flasher if your Sequential motor is turning. That flasher relay( K7 )is for the dash indicators to flash, not the turn signals.
It does however pass voltage to the Sequential motor through it’s coil. So if the motor turns, then it is passing voltage, whether or not it cycles properly for the dash.
So the motor turning is a key sign, check it! Then move on to that Seq Relay in the trunk. Big metal cover which loves to collect condensation and rust.
XR-7 should not matter for this circuit.
Wow, do I feel stupid. After reading the circuit diagrams again, I noticed an in-line fuse. So I went out and checked it in the harness, and it was blown. Replaced it and now everything works perfectly. YEAH!!!
HAHAHA, I guess I forgot to ask if the device was plugged in 
Fixed is fixed!
Wire 8 input power to TS/Hazard switch…you had brakes but no signals huh.