Correct - there is no relay for the turn signals on the vehicle proper, just for the trailer tow harness (same on XJ, AFAIK.) I may have an electronic version of the wiring diagrams on a hard drive somewhere, or have them on my RENIXPower group - you may want to check there. If
no dice, I should have a 1989 or 1990 electrical FSM handy (same thing either way,) and I can take a picture of ...