Ok there is only one wire with power under the seat. VERY WEAK VOLTAGE! I assume that it is for the sending unit. The relay will click when tested but I put different relay in and still nothing. Yes the inertia switch is fine and wired. I even took the one out of my coupe and put in his and still nothing. I dont need the inertia switch in mine but it is different then his. My car is a 90 and his is 89. Is there a difference in the chassis harness from 4 cyl to 8?